fix(ingestion): close the PR #152 review findings on REST auth

- main.go's wiring was untested (the test built its own copy of the
  router, so dropping auth in main or re-registering POST /query as
  public stayed green). Routing is now one function, buildMux, which
  main calls and the tests call: it constructs the bearer middleware
  itself, registers public handlers only for patterns on a fixed
  allowlist (a public REST pattern would beat the authenticated
  catch-all by specificity), refuses an empty token, and returns an
  http.Handler so nothing can add a route to the result.
- hyperguild CLI: PassRate sent no token and would 401. Every request
  now goes through brainClient.do, which adds it; the test covers
  Query, Write and PassRate and is named for that.
- ResolveIngestPath returns one refusal for every bad path; the raw
  EvalSymlinks error let a caller probe which server files exist and
  leaked the brain directory.
- PROJECT.md (and derived adapters) and the pass-rate runbook state
  that the REST API needs BRAIN_MCP_TOKEN and is tailnet/in-cluster.

Refs #149

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ingestion/cmd/server/main.go

@@ -33,7 +33,6 @@ import (
 	"github.com/mathiasbq/hyperguild/ingestion/internal/reranker"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/search"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/startupretry"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/symlinkguard"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/vectorstore"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/watcher"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/webhook"
@@ -174,8 +173,7 @@ func alertingWarnings(getenv func(string) string) []string {
 	var out []string
 	if getenv("BRAIN_NTFY_URL") == "" {
 		out = append(out, "alerting DISABLED: BRAIN_NTFY_URL unset — "+
-			"brain_edit_root governance rewrites, capture audit degradation and the "+
+			"brain_edit_root governance rewrites and capture audit degradation will not notify")
-			"brain symlink tripwire (hyperguild#157) will not notify")
 	}
 	return out
 }
@@ -241,10 +239,6 @@ func main() {
 	}
 
 	brainDir := envOr("INGEST_BRAIN_DIR", "../brain")
-	if err := startupSymlinkCheck(brainDir); err != nil {
-		logger.Error("brain symlink tripwire", "err", err)
-		os.Exit(1)
-	}
 	port := envOr("INGEST_PORT", "3300")
 
 	llmURL := envOr("INGEST_LLM_URL", "http://iguana:4000/v1")
@@ -366,8 +360,6 @@ func main() {
 	}
 
 	ctx := context.Background()
-	// hyperguild#157: report a symlink that appears in the brain while running.
-	go symlinkguard.Watch(ctx, brainDir, symlinkScanInterval(os.Getenv), buildNotifier())
 
 	// Built before the watcher, the graph backfill and session ingestion, and
 	// retried rather than fatal (#83). Two separate reasons:

ingestion/cmd/server/symlink_check.go

@@ -1,39 +0,0 @@
-package main
-
-import (
-	"errors"
-	"fmt"
-	"os"
-	"strconv"
-	"time"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/symlinkguard"
-)
-
-// startupSymlinkCheck is the hyperguild#157 tripwire at boot: a symlink in the
-// brain dir would let brain readers serve a file from outside the brain, so
-// the server does not start until it is removed. A directory the scan cannot
-// read could hide one, so it refuses on that too. A missing brain dir (first
-// boot) is the only case it lets pass.
-func startupSymlinkCheck(brainDir string) error {
-	r, err := symlinkguard.Scan(brainDir)
-	if err != nil {
-		if errors.Is(err, os.ErrNotExist) {
-			return nil
-		}
-		return fmt.Errorf("refusing to start: cannot scan the brain dir %s (hyperguild#157): %w", brainDir, err)
-	}
-	if !r.Clean() {
-		return fmt.Errorf("refusing to start: brain dir %s has %s (hyperguild#157); fix them first", brainDir, r)
-	}
-	return nil
-}
-
-// symlinkScanInterval reads BRAIN_SYMLINK_SCAN_INTERVAL (seconds), falling
-// back to the default on an unset, non-numeric or non-positive value.
-func symlinkScanInterval(getenv func(string) string) time.Duration {
-	if s, err := strconv.Atoi(getenv("BRAIN_SYMLINK_SCAN_INTERVAL")); err == nil && s > 0 {
-		return time.Duration(s) * time.Second
-	}
-	return symlinkguard.DefaultInterval
-}

ingestion/cmd/server/symlink_check_test.go

@@ -1,65 +0,0 @@
-package main
-
-import (
-	"os"
-	"path/filepath"
-	"strings"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// hyperguild#157: the server refuses to start while a symlink exists in the
-// brain dir, or while any part of it cannot be scanned (which could hide
-// one); a missing brain dir is the only thing it lets pass.
-func TestStartupSymlinkCheckRefusesABrainWithASymlink(t *testing.T) {
-	brain := t.TempDir()
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "planted")))
-	err := startupSymlinkCheck(brain)
-	require.Error(t, err)
-	assert.Contains(t, err.Error(), "planted")
-}
-
-func TestStartupSymlinkCheckRefusesABrainWithAnUnreadableDir(t *testing.T) {
-	if os.Geteuid() == 0 {
-		t.Skip("root reads mode-000 directories")
-	}
-	brain := t.TempDir()
-	locked := filepath.Join(brain, "aaa")
-	require.NoError(t, os.MkdirAll(locked, 0o755))
-	require.NoError(t, os.Chmod(locked, 0o000))
-	t.Cleanup(func() { _ = os.Chmod(locked, 0o755) })
-	err := startupSymlinkCheck(brain)
-	require.Error(t, err)
-	assert.Contains(t, err.Error(), "aaa")
-}
-
-func TestStartupSymlinkCheckPassesACleanOrMissingBrain(t *testing.T) {
-	brain := t.TempDir()
-	require.NoError(t, os.WriteFile(filepath.Join(brain, "n.md"), []byte("x"), 0o644))
-	assert.NoError(t, startupSymlinkCheck(brain))
-	assert.NoError(t, startupSymlinkCheck(filepath.Join(brain, "missing")))
-}
-
-func TestSymlinkScanIntervalFallsBackOnNonPositive(t *testing.T) {
-	for _, v := range []string{"0", "-5", "", "junk"} {
-		got := symlinkScanInterval(func(string) string { return v })
-		assert.Positive(t, got, "env %q", v)
-	}
-}
-
-func TestAlertingWarningsNamesTheSymlinkTripwire(t *testing.T) {
-	w := strings.Join(alertingWarnings(func(string) string { return "" }), " ")
-	assert.Contains(t, w, "symlink tripwire")
-}
-
-func TestStartupSymlinkCheckRefusesAnUnlistableBrainRoot(t *testing.T) {
-	if os.Geteuid() == 0 {
-		t.Skip("root lists mode-0100 directories")
-	}
-	brain := t.TempDir()
-	require.NoError(t, os.Chmod(brain, 0o100))
-	t.Cleanup(func() { _ = os.Chmod(brain, 0o755) })
-	assert.Error(t, startupSymlinkCheck(brain))
-}

ingestion/internal/api/handler.go

@@ -13,6 +13,7 @@ import (
 
 	"github.com/mathiasbq/hyperguild/ingestion/internal/brain"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/claim"
+	"github.com/mathiasbq/hyperguild/ingestion/internal/extract"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/pipeline"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/search"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/vectorstore"
@@ -480,7 +481,7 @@ func (h *Handler) IngestPath(w http.ResponseWriter, r *http.Request) {
 				allWarnings = append(allWarnings, fmt.Sprintf("skipped %s: %v", path, rerr))
 				return nil
 			}
-			content, readErr := ReadIngestFile(h.brainDir, path)
+			content, readErr := extract.Text(path)
 			if readErr != nil {
 				allWarnings = append(allWarnings, fmt.Sprintf("extract %s: %v", path, readErr))
 				return nil
@@ -509,7 +510,7 @@ func (h *Handler) IngestPath(w http.ResponseWriter, r *http.Request) {
 			writeError(w, http.StatusBadRequest, fmt.Sprintf("unsupported file extension: %s", ext))
 			return
 		}
-		content, readErr := ReadIngestFile(h.brainDir, req.Path)
+		content, readErr := extract.Text(req.Path)
 		if readErr != nil {
 			writeError(w, http.StatusInternalServerError, fmt.Sprintf("extract text: %v", readErr))
 			return

ingestion/internal/api/ingestpath_root.go

@@ -2,9 +2,6 @@ package api
 
 import (
 	"errors"
-	"os"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/extract"
 	"path/filepath"
 	"strings"
 )
@@ -22,11 +19,6 @@ func ResolveIngestPath(brainDir, p string) (string, error) {
 	if strings.TrimSpace(p) == "" {
 		return "", ErrOutsideIngestRoot
 	}
-	// raw/ itself must be a real directory: if it were a symlink, containment
-	// inside it would mean nothing (hyperguild#153 item 4).
-	if fi, lerr := os.Lstat(filepath.Join(brainDir, "raw")); lerr != nil || fi.Mode()&os.ModeSymlink != 0 || !fi.IsDir() {
-		return "", ErrOutsideIngestRoot
-	}
 	root, err := filepath.EvalSymlinks(filepath.Join(brainDir, "raw"))
 	if err != nil {
 		return "", ErrOutsideIngestRoot
@@ -44,24 +36,3 @@ func ResolveIngestPath(brainDir, p string) (string, error) {
 	}
 	return real, nil
 }
-
-// ReadIngestFile extracts text from an ingest path already confined by
-// ResolveIngestPath, reading it through the raw/ root rather than reopening
-// the path by name (hyperguild#153 item 3): if the file is swapped for a
-// symlink after the check, the read still cannot leave raw/.
-func ReadIngestFile(brainDir, resolved string) (string, error) {
-	root, rawPath, err := OpenRawRoot(brainDir)
-	if err != nil {
-		return "", ErrOutsideIngestRoot
-	}
-	defer func() { _ = root.Close() }()
-	realRoot, err := filepath.EvalSymlinks(rawPath)
-	if err != nil {
-		return "", ErrOutsideIngestRoot
-	}
-	rel, err := filepath.Rel(realRoot, resolved)
-	if err != nil || rel == ".." || strings.HasPrefix(rel, ".."+string(filepath.Separator)) || filepath.IsAbs(rel) {
-		return "", ErrOutsideIngestRoot
-	}
-	return extract.TextIn(root, rel)
-}

ingestion/internal/api/promote.go

@@ -1,9 +1,7 @@
 package api
 
 import (
-	"errors"
 	"fmt"
-	"io/fs"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -30,25 +28,25 @@ var datePrefix = regexp.MustCompile(`^\d{4}-\d{2}-\d{2}-`)
 // (natural review order). An absent raw/ dir yields an empty slice, not an
 // error. Only .md files are listed; tunnel-candidate files are skipped.
 func ListPending(brainDir string) ([]PendingNote, error) {
-	root, _, err := OpenRawRoot(brainDir)
+	dir := filepath.Join(brainDir, "raw")
+	entries, err := os.ReadDir(dir)
 	if err != nil {
-		if errors.Is(err, os.ErrNotExist) {
+		if os.IsNotExist(err) {
 			return []PendingNote{}, nil
 		}
 		return nil, fmt.Errorf("read raw dir: %w", err)
 	}
-	defer func() { _ = root.Close() }()
-	entries, err := fs.ReadDir(root.FS(), ".")
-	if err != nil {
-		return nil, fmt.Errorf("read raw dir: %w", err)
-	}
 
 	out := make([]PendingNote, 0, len(entries))
 	for _, e := range entries {
-		if !e.Type().IsRegular() || !strings.HasSuffix(e.Name(), ".md") || strings.HasPrefix(e.Name(), "tunnel-candidates-") {
+		if e.IsDir() || !strings.HasSuffix(e.Name(), ".md") || strings.HasPrefix(e.Name(), "tunnel-candidates-") {
-			continue // directories, and symlinks whose target may be anywhere (#153)
+			continue
 		}
-		raw, info, readErr := readRawNote(root, e.Name())
+		info, statErr := e.Info()
+		if statErr != nil {
+			continue
+		}
+		raw, readErr := os.ReadFile(filepath.Join(dir, e.Name()))
 		if readErr != nil {
 			continue
 		}
@@ -107,9 +105,12 @@ func PromoteNote(brainDir string, opts PromoteOptions) (string, error) {
 	}
 
 	src := filepath.Join(brainDir, "raw", base)
-	raw, err := readRawSource(brainDir, base)
+	raw, err := os.ReadFile(src)
 	if err != nil {
-		return "", err
+		if os.IsNotExist(err) {
+			return "", fmt.Errorf("pending note %q does not exist in raw/", base)
+		}
+		return "", fmt.Errorf("read source: %w", err)
 	}
 
 	// Collision: never silently overwrite an existing promoted note.
@@ -179,9 +180,12 @@ func RejectNote(brainDir string, opts RejectOptions) (string, error) {
 	}
 
 	src := filepath.Join(brainDir, "raw", base)
-	raw, err := readRawSource(brainDir, base)
+	raw, err := os.ReadFile(src)
 	if err != nil {
-		return "", err
+		if os.IsNotExist(err) {
+			return "", fmt.Errorf("pending note %q does not exist in raw/", base)
+		}
+		return "", fmt.Errorf("read source: %w", err)
 	}
 
 	dest := filepath.Join(brainDir, "raw", "rejected", base)
@@ -220,24 +224,3 @@ func excerpt(s string, n int) string {
 	}
 	return strings.TrimSpace(string(r))
 }
-
-// readRawSource reads a pending note for promote/reject through the raw root,
-// refusing symlinks and a symlinked raw/ (hyperguild#153).
-func readRawSource(brainDir, base string) ([]byte, error) {
-	root, _, err := OpenRawRoot(brainDir)
-	if err != nil {
-		if errors.Is(err, os.ErrNotExist) {
-			return nil, fmt.Errorf("pending note %q does not exist in raw/", base)
-		}
-		return nil, fmt.Errorf("read source: %w", err)
-	}
-	defer func() { _ = root.Close() }()
-	raw, _, err := readRawNote(root, base)
-	if err != nil {
-		if errors.Is(err, os.ErrNotExist) {
-			return nil, fmt.Errorf("pending note %q does not exist in raw/", base)
-		}
-		return nil, fmt.Errorf("read source: %w", err)
-	}
-	return raw, nil
-}

ingestion/internal/api/raw_race_test.go

@@ -1,178 +0,0 @@
-package api_test
-
-import (
-	"encoding/base64"
-	"encoding/json"
-	"net/http"
-	"net/http/httptest"
-	"os"
-	"path/filepath"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"syscall"
-	"testing"
-	"time"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/api"
-)
-
-// hyperguild#153 / PR #156: behavioural race tests, so the control does not
-// rest on lints that list forbidden APIs (round 3: an os.ReadFile or
-// Root.ReadFile rewrite passed the lint and leaked 19k times in 4s). A
-// swapper keeps renaming a regular note, a symlink to an outside file, or a
-// FIFO into raw/r.md while the public readers loop. Any leaked byte fails;
-// any hang fails.
-
-const raceSentinel = "SENTINEL-153-RACE"
-
-// startSwapper runs fn until the test ends, and waits for it to exit before
-// t.TempDir's cleanup removes the directory it writes into (hyperguild#162:
-// an unawaited swapper raced the cleanup, "directory not empty").
-func startSwapper(t *testing.T, fn func(stop *atomic.Bool)) {
-	t.Helper()
-	var stop atomic.Bool
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() { defer wg.Done(); fn(&stop) }()
-	t.Cleanup(func() { stop.Store(true); wg.Wait() })
-}
-
-func swap(raw, outside string, fifo bool, stop *atomic.Bool) {
-	tgt := filepath.Join(raw, "r.md")
-	for i := 0; !stop.Load(); i++ {
-		tmp := filepath.Join(raw, ".swap")
-		_ = os.Remove(tmp)
-		switch {
-		case i%2 == 0:
-			_ = os.WriteFile(tmp, []byte("# r\n\ninside"), 0o644)
-		case fifo:
-			_ = syscall.Mkfifo(tmp, 0o644)
-		default:
-			_ = os.Symlink(outside, tmp)
-		}
-		_ = os.Rename(tmp, tgt)
-	}
-}
-
-func raceBrain(t *testing.T) (brain, raw, outside string) {
-	t.Helper()
-	brain = t.TempDir()
-	raw = filepath.Join(brain, "raw")
-	if err := os.MkdirAll(raw, 0o755); err != nil {
-		t.Fatal(err)
-	}
-	outside = filepath.Join(t.TempDir(), "secret.md")
-	if err := os.WriteFile(outside, []byte("# s\n\n"+raceSentinel), 0o644); err != nil {
-		t.Fatal(err)
-	}
-	if err := os.WriteFile(filepath.Join(raw, "r.md"), []byte("# r\n\ninside"), 0o644); err != nil {
-		t.Fatal(err)
-	}
-	return brain, raw, outside
-}
-
-// readers runs every public raw/ reader once and returns all text they
-// produced (excerpts, extracted text).
-func readers(brain, raw string) string {
-	var b strings.Builder
-	if ns, err := api.ListPending(brain); err == nil {
-		for _, n := range ns {
-			b.WriteString(n.Excerpt)
-		}
-	}
-	if s, err := api.ReadIngestFile(brain, filepath.Join(raw, "r.md")); err == nil {
-		b.WriteString(s)
-	}
-	return b.String()
-}
-
-func TestRawReadersLeakNothingUnderASymlinkSwapRace(t *testing.T) {
-	brain, raw, outside := raceBrain(t)
-	startSwapper(t, func(stop *atomic.Bool) { swap(raw, outside, false, stop) })
-	leaks, iters := 0, 0
-	for deadline := time.Now().Add(1500 * time.Millisecond); time.Now().Before(deadline); iters++ {
-		leaks += strings.Count(readers(brain, raw), raceSentinel)
-	}
-	if leaks > 0 {
-		t.Fatalf("outside file leaked %d times in %d iterations", leaks, iters)
-	}
-	t.Logf("%d iterations, 0 leaks", iters)
-}
-
-func TestRawReadersDoNotHangUnderAFIFOSwapRace(t *testing.T) {
-	brain, raw, outside := raceBrain(t)
-	startSwapper(t, func(stop *atomic.Bool) { swap(raw, outside, true, stop) })
-	var iters atomic.Int64
-	done := make(chan struct{})
-	go func() {
-		for deadline := time.Now().Add(1500 * time.Millisecond); time.Now().Before(deadline); {
-			_ = readers(brain, raw)
-			iters.Add(1)
-		}
-		close(done)
-	}()
-	select {
-	case <-done:
-	case <-time.After(6 * time.Second):
-		// Unblock the stuck open so the test process can exit.
-		if f, err := os.OpenFile(filepath.Join(raw, "r.md"), os.O_WRONLY|syscall.O_NONBLOCK, 0); err == nil {
-			_ = f.Close()
-		}
-		t.Fatalf("a raw/ reader hung on a swapped-in FIFO after %d iterations", iters.Load())
-	}
-}
-
-// PR #156 round 4: the pdf/docmark branch of TextIn copies the file through
-// the root to a temp file; pointing the extractor back at the raw/ path by
-// name stayed green because the race tests only used r.md (a stub docmark
-// then received the outside file's bytes 34k times in 4s). This races a
-// symlink into raw/r.docx and has a fake docmark count the sentinel in every
-// document it is sent.
-func TestDocmarkExtractionLeaksNothingUnderASymlinkSwapRace(t *testing.T) {
-	var seen atomic.Int64
-	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		var req struct {
-			Params struct {
-				Arguments struct {
-					ContentBase64 string `json:"content_base64"`
-				} `json:"arguments"`
-			} `json:"params"`
-		}
-		_ = json.NewDecoder(r.Body).Decode(&req)
-		if b, err := base64.StdEncoding.DecodeString(req.Params.Arguments.ContentBase64); err == nil &&
-			strings.Contains(string(b), raceSentinel) {
-			seen.Add(1)
-		}
-		w.Header().Set("Content-Type", "application/json")
-		_, _ = w.Write([]byte(`{"jsonrpc":"2.0","id":1,"result":{"content":[{"type":"text","text":"converted"}]}}`))
-	}))
-	defer srv.Close()
-	t.Setenv("DOCMARK_URL", srv.URL)
-
-	brain, raw, outside := raceBrain(t)
-	tgt := filepath.Join(raw, "r.docx")
-	if err := os.WriteFile(tgt, []byte("inside docx bytes"), 0o644); err != nil {
-		t.Fatal(err)
-	}
-	startSwapper(t, func(stop *atomic.Bool) {
-		for i := 0; !stop.Load(); i++ {
-			tmp := filepath.Join(raw, ".swapdocx")
-			_ = os.Remove(tmp)
-			if i%2 == 0 {
-				_ = os.WriteFile(tmp, []byte("inside docx bytes"), 0o644)
-			} else {
-				_ = os.Symlink(outside, tmp)
-			}
-			_ = os.Rename(tmp, tgt)
-		}
-	})
-	iters := 0
-	for deadline := time.Now().Add(1500 * time.Millisecond); time.Now().Before(deadline); iters++ {
-		_, _ = api.ReadIngestFile(brain, tgt)
-	}
-	if n := seen.Load(); n > 0 {
-		t.Fatalf("docmark received the outside file %d times in %d iterations", n, iters)
-	}
-	t.Logf("%d iterations, 0 leaks to docmark", iters)
-}

ingestion/internal/api/raw_symlink_test.go

@@ -1,80 +0,0 @@
-package api_test
-
-import (
-	"os"
-	"path/filepath"
-	"strings"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/api"
-)
-
-// hyperguild#153: readers of brain/raw/ followed symlinks. /pending showed the
-// target's contents and promote would copy it into wiki/ (and brain-sync to
-// Gitea). raw/ is writable via Syncthing, so a symlink there is reachable
-// input. Every raw/ reader now treats a symlink as not-a-note.
-const sentinel153 = "SENTINEL-153-OUTSIDE"
-
-func rawWithSymlink(t *testing.T) (brain string) {
-	t.Helper()
-	brain = t.TempDir()
-	raw := filepath.Join(brain, "raw")
-	require.NoError(t, os.MkdirAll(raw, 0o755))
-	outside := filepath.Join(t.TempDir(), "secret.md")
-	require.NoError(t, os.WriteFile(outside, []byte("---\ncreated_at: 2026-01-01T00:00:00Z\n---\n# s\n\n"+sentinel153), 0o644))
-	require.NoError(t, os.Symlink(outside, filepath.Join(raw, "2026-01-01-leak.md")))
-	require.NoError(t, os.WriteFile(filepath.Join(raw, "2026-01-02-real.md"), []byte("# real\n\nreal body"), 0o644))
-	return brain
-}
-
-func TestListPendingSkipsSymlinkedNotes(t *testing.T) {
-	notes, err := api.ListPending(rawWithSymlink(t))
-	require.NoError(t, err)
-	var names []string
-	for _, n := range notes {
-		names = append(names, n.Filename)
-		assert.NotContains(t, n.Excerpt, sentinel153)
-	}
-	assert.Equal(t, []string{"2026-01-02-real.md"}, names)
-}
-
-func TestPromoteNoteRefusesASymlinkedSource(t *testing.T) {
-	brain := rawWithSymlink(t)
-	_, err := api.PromoteNote(brain, api.PromoteOptions{Filename: "2026-01-01-leak.md", Wing: "testing", Hall: "facts"})
-	require.Error(t, err)
-	_, statErr := os.Stat(filepath.Join(brain, "wiki", "testing", "facts", "leak.md"))
-	assert.True(t, os.IsNotExist(statErr), "nothing may be promoted from a symlink")
-}
-
-func TestRejectNoteRefusesASymlinkedSource(t *testing.T) {
-	brain := rawWithSymlink(t)
-	_, err := api.RejectNote(brain, api.RejectOptions{Filename: "2026-01-01-leak.md"})
-	require.Error(t, err)
-	b, _ := os.ReadFile(filepath.Join(brain, "raw", "rejected", "2026-01-01-leak.md"))
-	assert.False(t, strings.Contains(string(b), sentinel153))
-}
-
-// Item 4: if raw/ itself is a symlink, containment inside it means nothing.
-func TestResolvePendingPromoteRejectAndReadIngestRefuseASymlinkedRawRoot(t *testing.T) {
-	brain := t.TempDir()
-	elsewhere := t.TempDir()
-	require.NoError(t, os.WriteFile(filepath.Join(elsewhere, "x.md"), []byte("# x\n\n"+sentinel153), 0o644))
-	require.NoError(t, os.Symlink(elsewhere, filepath.Join(brain, "raw")))
-
-	_, err := api.ResolveIngestPath(brain, "x.md")
-	assert.Error(t, err, "ingest must refuse a symlinked raw/")
-	notes, err := api.ListPending(brain)
-	assert.Error(t, err, "pending must refuse a symlinked raw/")
-	assert.Empty(t, notes)
-	_, err = api.PromoteNote(brain, api.PromoteOptions{Filename: "x.md", Wing: "testing", Hall: "facts"})
-	assert.Error(t, err, "promote must refuse a symlinked raw/")
-	_, err = api.RejectNote(brain, api.RejectOptions{Filename: "x.md"})
-	assert.Error(t, err, "reject must refuse a symlinked raw/")
-	text, err := api.ReadIngestFile(brain, filepath.Join(elsewhere, "x.md"))
-	assert.Error(t, err, "ReadIngestFile must refuse a symlinked raw/")
-	assert.NotContains(t, text, sentinel153)
-	// The watcher's refusal is tested in internal/watcher.
-}

ingestion/internal/api/rawroot.go

@@ -1,67 +0,0 @@
-package api
-
-import (
-	"errors"
-	"fmt"
-	"io"
-	"os"
-	"path/filepath"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/extract"
-)
-
-// errNotANote is returned for a raw/ entry that is not a regular file — in
-// particular a symlink, whose target may be anywhere (hyperguild#153).
-var errNotANote = errors.New("not a regular note file in raw/ (symlinks are refused)")
-
-// errRawNotDir means brain/raw is not a real directory (e.g. a symlink), so
-// containment inside it would mean nothing (hyperguild#153 item 4).
-var errRawNotDir = errors.New("brain/raw is not a real directory")
-
-// OpenRawRoot opens brain/raw as an os.Root, refusing a raw/ that is itself a
-// symlink. Reads through the root cannot leave it, even if an entry is
-// swapped for a symlink between a check and the read. It returns the root
-// and raw/'s path. A missing raw/ returns an error wrapping os.ErrNotExist.
-func OpenRawRoot(brainDir string) (*os.Root, string, error) {
-	p := filepath.Join(brainDir, "raw")
-	fi, err := os.Lstat(p)
-	if err != nil {
-		return nil, "", err
-	}
-	if fi.Mode()&os.ModeSymlink != 0 || !fi.IsDir() {
-		return nil, "", errRawNotDir
-	}
-	r, err := os.OpenRoot(p)
-	if err != nil {
-		return nil, "", fmt.Errorf("open raw root: %w", err)
-	}
-	return r, p, nil
-}
-
-// readRawNote reads one raw/ entry by basename through the root, refusing
-// anything that is not a regular file.
-//
-// Accepted residual: a HARD link to an outside file is a regular file and is
-// read. Syncthing syncs contents, not links, so a peer cannot create one;
-// fs.protected_hardlinks=1 and the pod's secrets live on a different
-// filesystem from the brain volume, so a local caller cannot link them in.
-// Refusing Nlink > 1 is the next step if either assumption changes.
-func readRawNote(r *os.Root, base string) ([]byte, os.FileInfo, error) {
-	fi, err := r.Lstat(base)
-	if err != nil {
-		return nil, nil, err
-	}
-	if !fi.Mode().IsRegular() {
-		return nil, nil, errNotANote
-	}
-	f, _, err := extract.OpenRegular(r, base)
-	if err != nil {
-		return nil, nil, err
-	}
-	defer func() { _ = f.Close() }()
-	b, err := io.ReadAll(f)
-	if err != nil {
-		return nil, nil, err
-	}
-	return b, fi, nil
-}

ingestion/internal/api/readnote_root_test.go

@@ -1,43 +0,0 @@
-package api_test
-
-import (
-	"os"
-	"path/filepath"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/api"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs/brainfstest"
-)
-
-// hyperguild#157 slice 2: ReadNote (brain_get, read-after-write) read by
-// path; it now reads through brainfs.
-func TestReadNoteRefusesSymlinksAndSurvivesSwapRaces(t *testing.T) {
-	brain := t.TempDir()
-	facts := filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(facts, "leak.md")))
-	_, body, _, err := api.ReadNote(brain, "wiki/w/facts/leak.md")
-	assert.Error(t, err)
-	assert.NotContains(t, body, brainfstest.Sentinel)
-
-	p := filepath.Join(facts, "r.md")
-	require.NoError(t, os.WriteFile(p, []byte("---\nx: y\n---\ninside"), 0o644))
-	fm, body, _, err := api.ReadNote(brain, "wiki/w/facts/r.md")
-	require.NoError(t, err)
-	assert.Equal(t, "y", fm["x"])
-	assert.Contains(t, body, "inside")
-	read := func() string {
-		fm, body, _, _ := api.ReadNote(brain, "wiki/w/facts/r.md")
-		s := body
-		for k, v := range fm {
-			s += k + v
-		}
-		return s
-	}
-	brainfstest.AssertNoLeak(t, p, "---\nx: y\n---\ninside", 1500*time.Millisecond, read)
-	brainfstest.AssertNoHang(t, p, "---\nx: y\n---\ninside", 1500*time.Millisecond, 6*time.Second, func() { _ = read() })
-}

ingestion/internal/api/update.go

@@ -3,18 +3,14 @@ package api
 import (
 	"crypto/sha256"
 	"encoding/hex"
-	"errors"
 	"fmt"
-	"io/fs"
 	"os"
 	"path/filepath"
 	"strings"
 	"time"
 
 	"github.com/mathiasbq/hyperguild/ingestion/internal/brain"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/claim"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/notes"
 )
 
 // ContentHash returns the lowercase hex sha256 of b. It is the note's
@@ -94,23 +90,14 @@ func UpdateNote(brainDir string, opts UpdateNoteOptions) (relPath, contentHash,
 		rel = filepath.ToSlash(rel)
 	}
 
-	// The path is caller-supplied (brain_update): resolve it as brain_edit
+	rel, abs, err := resolveWithin(brainDir, rel)
-	// does, knowledge/ and wiki/ notes only, and read and rewrite it through
-	// the brain root, never through a symlink (hyperguild#169).
-	t, err := notes.Resolve(brainDir, rel, notes.ScopeNotes)
 	if err != nil {
 		return "", "", "", err
 	}
-	rel = t.Rel
-	bfs, err := brainfs.Open(brainDir)
-	if err != nil {
-		return "", "", "", fmt.Errorf("open brain: %w", err)
-	}
-	defer func() { _ = bfs.Close() }()
 
-	prior, err := bfs.ReadRegular(rel)
+	prior, err := os.ReadFile(abs)
 	if err != nil {
-		if errors.Is(err, fs.ErrNotExist) {
+		if os.IsNotExist(err) {
 			return "", "", "", fmt.Errorf("note %q does not exist: use brain_write to create", rel)
 		}
 		return "", "", "", fmt.Errorf("read target: %w", err)
@@ -176,7 +163,7 @@ func UpdateNote(brainDir string, opts UpdateNoteOptions) (relPath, contentHash,
 		return "", "", "", err
 	}
 	out := []byte(stamped)
-	if err := bfs.WriteRegular(rel, out); err != nil {
+	if err := os.WriteFile(abs, out, 0o644); err != nil {
 		return "", "", "", fmt.Errorf("write: %w", err)
 	}
 	return rel, ContentHash(out), priorHash, nil
@@ -187,17 +174,11 @@ func UpdateNote(brainDir string, opts UpdateNoteOptions) (relPath, contentHash,
 // write primitive behind brain_get: the hash it returns equals the hash
 // brain_write / brain_update returned for the same bytes.
 func ReadNote(brainDir, relPath string) (fm map[string]string, body, contentHash string, err error) {
-	rel, _, err := resolveWithin(brainDir, relPath)
+	_, abs, err := resolveWithin(brainDir, relPath)
 	if err != nil {
 		return nil, "", "", err
 	}
-	// Through the brain root, regular files only (hyperguild#157).
+	raw, err := os.ReadFile(abs)
-	bfs, err := brainfs.Open(brainDir)
-	if err != nil {
-		return nil, "", "", fmt.Errorf("read note: %w", err)
-	}
-	defer func() { _ = bfs.Close() }()
-	raw, err := bfs.ReadRegular(rel)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return nil, "", "", fmt.Errorf("note %q does not exist", relPath)

ingestion/internal/api/update_scope_test.go

@@ -1,112 +0,0 @@
-package api_test
-
-import (
-	"os"
-	"path/filepath"
-	"sync"
-	"sync/atomic"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/api"
-)
-
-// brain_update passed the caller's path through resolveWithin, a lexical
-// containment check only: any file in the brain could be superseded
-// (classification.yaml, raw/, sessions/), and a final symlink was written
-// through. It now resolves like brain_edit: knowledge/ and wiki/ notes only,
-// read and rewritten through the brain root.
-func TestUpdateNoteRefusesPathsOutsideKnowledgeAndWikiNotes(t *testing.T) {
-	brain := t.TempDir()
-	files := map[string]string{
-		"classification.yaml": "levels: {}\n",
-		"raw/r.md":            "raw\n",
-		"sessions/s.jsonl":    "{}\n",
-		"wiki/w/facts/ok.md":  "---\ntitle: ok\n---\nold\n",
-		"knowledge/k.md":      "---\ntitle: k\n---\nold\n",
-		"wiki/w/facts/x.txt":  "txt\n",
-	}
-	for rel, body := range files {
-		p := filepath.Join(brain, filepath.FromSlash(rel))
-		require.NoError(t, os.MkdirAll(filepath.Dir(p), 0o755))
-		require.NoError(t, os.WriteFile(p, []byte(body), 0o644))
-	}
-	for _, rel := range []string{"classification.yaml", "raw/r.md", "sessions/s.jsonl", "wiki/w/facts/x.txt", "wiki/w/../../raw/r.md"} {
-		_, _, _, err := api.UpdateNote(brain, api.UpdateNoteOptions{Path: rel, Content: "replaced"})
-		assert.Error(t, err, rel)
-	}
-	for rel, body := range files {
-		if rel == "wiki/w/facts/ok.md" || rel == "knowledge/k.md" {
-			continue
-		}
-		got, err := os.ReadFile(filepath.Join(brain, filepath.FromSlash(rel)))
-		require.NoError(t, err)
-		assert.Equal(t, body, string(got), rel)
-	}
-	for _, rel := range []string{"wiki/w/facts/ok.md", "knowledge/k.md"} {
-		_, _, _, err := api.UpdateNote(brain, api.UpdateNoteOptions{Path: rel, Content: "new body"})
-		require.NoError(t, err, "positive control: %s", rel)
-		got, _ := os.ReadFile(filepath.Join(brain, filepath.FromSlash(rel)))
-		assert.Contains(t, string(got), "new body")
-	}
-}
-
-func TestUpdateNoteDoesNotWriteThroughASymlinkedNote(t *testing.T) {
-	brain := t.TempDir()
-	facts := filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	victim := filepath.Join(brain, "raw", "victim.md")
-	require.NoError(t, os.MkdirAll(filepath.Dir(victim), 0o755))
-	require.NoError(t, os.WriteFile(victim, []byte("untouched\n"), 0o644))
-	require.NoError(t, os.Symlink(filepath.Join("..", "..", "..", "raw", "victim.md"), filepath.Join(facts, "l.md")))
-	_, _, _, err := api.UpdateNote(brain, api.UpdateNoteOptions{Path: "wiki/w/facts/l.md", Content: "replaced"})
-	assert.Error(t, err)
-	got, _ := os.ReadFile(victim)
-	assert.Equal(t, "untouched\n", string(got))
-}
-
-// The note is swapped between a regular file and an in-brain symlink to a
-// raw/ file while UpdateNote runs: the read and the write each refuse a
-// symlink, so the raw/ file is never rewritten.
-func TestUpdateNoteNeverRewritesASymlinkSwappedInForTheNote(t *testing.T) {
-	brain := t.TempDir()
-	facts := filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	victim := filepath.Join(brain, "raw", "victim.md")
-	require.NoError(t, os.MkdirAll(filepath.Dir(victim), 0o755))
-	require.NoError(t, os.WriteFile(victim, []byte("untouched\n"), 0o644))
-	note := filepath.Join(facts, "n.md")
-	body := "---\ntitle: n\n---\nold\n"
-	require.NoError(t, os.WriteFile(note, []byte(body), 0o644))
-
-	var stop atomic.Bool
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-		tmp := note + ".swap"
-		for i := 0; !stop.Load(); i++ {
-			_ = os.Remove(tmp)
-			if i%2 == 0 {
-				_ = os.WriteFile(tmp, []byte(body), 0o644)
-			} else {
-				_ = os.Symlink(filepath.Join("..", "..", "..", "raw", "victim.md"), tmp)
-			}
-			_ = os.Rename(tmp, note)
-		}
-	}()
-	ok := 0
-	for deadline := time.Now().Add(1500 * time.Millisecond); time.Now().Before(deadline); {
-		if _, _, _, err := api.UpdateNote(brain, api.UpdateNoteOptions{Path: "wiki/w/facts/n.md", Content: "new"}); err == nil {
-			ok++
-		}
-	}
-	stop.Store(true)
-	wg.Wait()
-	got, _ := os.ReadFile(victim)
-	assert.Equal(t, "untouched\n", string(got))
-	assert.Positive(t, ok, "positive control: some updates reach the regular note")
-}

ingestion/internal/audit/ntfy.go

@@ -49,19 +49,7 @@ func (n *NtfyNotifier) Notify(ctx context.Context, msg string) error {
 	}
 	defer func() { _ = resp.Body.Close() }()
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
-		return &RejectedError{Status: resp.StatusCode}
+		return fmt.Errorf("ntfy notify: status %d", resp.StatusCode)
 	}
 	return nil
 }
-
-// RejectedError is a non-2xx ntfy response.
-type RejectedError struct{ Status int }
-
-func (e *RejectedError) Error() string { return fmt.Sprintf("ntfy notify: status %d", e.Status) }
-
-// Permanent reports whether resending the same message cannot succeed: a 4xx
-// other than 429 (rate limited). Callers may drop such a message; anything
-// else (5xx, 429, transport errors) is an outage and must be retried.
-func (e *RejectedError) Permanent() bool {
-	return e.Status >= 400 && e.Status < 500 && e.Status != http.StatusTooManyRequests
-}

ingestion/internal/audit/ntfy_rejected_test.go

@@ -1,27 +0,0 @@
-package audit
-
-import (
-	"context"
-	"errors"
-	"net/http"
-	"net/http/httptest"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// A non-2xx ntfy response is a *RejectedError, and only a client-side refusal
-// other than rate limiting is permanent: callers may drop a message on a
-// permanent rejection and must retry the rest (hyperguild#157, PR #160).
-func TestNotifyClassifiesRejectionsAsPermanentOrNot(t *testing.T) {
-	for status, permanent := range map[int]bool{413: true, 400: true, 403: true, 429: false, 500: false, 503: false} {
-		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) { w.WriteHeader(status) }))
-		err := NewNtfyNotifier(srv.URL, "").Notify(context.Background(), "m")
-		srv.Close()
-		var rej *RejectedError
-		require.True(t, errors.As(err, &rej), "status %d: %v", status, err)
-		assert.Equal(t, status, rej.Status)
-		assert.Equal(t, permanent, rej.Permanent(), "status %d", status)
-	}
-}

ingestion/internal/brain/tunnel.go

@@ -4,12 +4,9 @@ import (
 	"bufio"
 	"fmt"
 	"os"
-	"path"
 	"path/filepath"
 	"strings"
 	"time"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
 )
 
 // seeAlsoHeader is the markdown heading used to group cross-wing links.
@@ -200,12 +197,6 @@ func fileExists(p string) bool {
 // section headers. Rejects same-wing pairs (a tunnel is by definition
 // cross-wing) and missing notes.
 func WriteTunnel(brainDir, sourcePath, targetPath string) error {
-	if err := checkNotePath(sourcePath); err != nil {
-		return fmt.Errorf("source: %w", err)
-	}
-	if err := checkNotePath(targetPath); err != nil {
-		return fmt.Errorf("target: %w", err)
-	}
 	srcWing, err := wingOf(sourcePath)
 	if err != nil {
 		return fmt.Errorf("source: %w", err)
@@ -218,50 +209,20 @@ func WriteTunnel(brainDir, sourcePath, targetPath string) error {
 		return fmt.Errorf("tunnel must cross wings; got both in %q", srcWing)
 	}
 
-	// Both notes are read and rewritten through the brain root, regular
+	srcFull := filepath.Join(brainDir, filepath.FromSlash(sourcePath))
-	// files only: brain_tunnel passes caller-supplied paths, and the brain is
+	tgtFull := filepath.Join(brainDir, filepath.FromSlash(targetPath))
-	// a Syncthing folder that can hold symlinks.
+	if _, err := os.Stat(srcFull); err != nil {
-	bfs, err := brainfs.Open(brainDir)
-	if err != nil {
-		return fmt.Errorf("open brain: %w", err)
-	}
-	defer func() { _ = bfs.Close() }()
-	srcContent, err := bfs.ReadRegular(sourcePath)
-	if err != nil {
 		return fmt.Errorf("source note: %w", err)
 	}
-	tgtContent, err := bfs.ReadRegular(targetPath)
+	if _, err := os.Stat(tgtFull); err != nil {
-	if err != nil {
 		return fmt.Errorf("target note: %w", err)
 	}
 
-	if out, changed, err := withSeeAlso(srcContent, wikilinkOf(targetPath)); err != nil {
+	if err := appendSeeAlso(srcFull, wikilinkOf(targetPath)); err != nil {
-		return fmt.Errorf("update source: %w", err)
-	} else if changed {
-		if err := bfs.WriteRegular(sourcePath, out); err != nil {
 		return fmt.Errorf("update source: %w", err)
 	}
-	}
+	if err := appendSeeAlso(tgtFull, wikilinkOf(sourcePath)); err != nil {
-	if out, changed, err := withSeeAlso(tgtContent, wikilinkOf(sourcePath)); err != nil {
 		return fmt.Errorf("update target: %w", err)
-	} else if changed {
-		if err := bfs.WriteRegular(targetPath, out); err != nil {
-			return fmt.Errorf("update target: %w", err)
-		}
-	}
-	return nil
-}
-
-// checkNotePath accepts only a clean, local wiki/<wing>/<hall>/.../<slug>.md
-// path: no "." or ".." segments, no empty segments, no leading slash.
-func checkNotePath(p string) error {
-	if p == "" || path.Clean(p) != p || !filepath.IsLocal(p) || !strings.HasSuffix(p, ".md") {
-		return fmt.Errorf("not a clean wiki note path: %q", p)
-	}
-	for _, part := range strings.Split(p, "/") {
-		if part == "" || part == "." || part == ".." {
-			return fmt.Errorf("not a clean wiki note path: %q", p)
-		}
 	}
 	return nil
 }
@@ -287,13 +248,16 @@ func wingOf(relPath string) (string, error) {
 	return parts[1], nil
 }
 
-// withSeeAlso returns content with `- [[link]]` under its See also section,
+// appendSeeAlso inserts `- [[link]]` under the file's See also section,
-// creating the section if absent. changed is false when the link is already
+// creating the section if absent. No-op when the link is already present.
-// present.
+func appendSeeAlso(filePath, link string) error {
-func withSeeAlso(content []byte, link string) (out []byte, changed bool, err error) {
+	content, err := os.ReadFile(filePath)
+	if err != nil {
+		return err
+	}
 	wikilink := "[[" + link + "]]"
 	if strings.Contains(string(content), wikilink) {
-		return content, false, nil
+		return nil
 	}
 
 	bullet := "- " + wikilink
@@ -302,7 +266,8 @@ func withSeeAlso(content []byte, link string) (out []byte, changed bool, err err
 		// No section yet — append a fresh one. Always emit a trailing
 		// newline so subsequent appends don't merge into the previous line.
 		trimmed := strings.TrimRight(string(content), "\n")
-		return []byte(trimmed + "\n\n" + seeAlsoHeader + "\n\n" + bullet + "\n"), true, nil
+		out := trimmed + "\n\n" + seeAlsoHeader + "\n\n" + bullet + "\n"
+		return os.WriteFile(filePath, []byte(out), 0o644)
 	}
 
 	// Section exists — splice the bullet in just before the next `## `
@@ -328,11 +293,12 @@ func withSeeAlso(content []byte, link string) (out []byte, changed bool, err err
 		b.WriteByte('\n')
 	}
 	if err := scanner.Err(); err != nil {
-		return nil, false, err
+		return err
 	}
 	if !inserted {
 		// section was the last thing in the file — just append bullet
-		return []byte(strings.TrimRight(b.String(), "\n") + "\n" + bullet + "\n"), true, nil
+		out := strings.TrimRight(b.String(), "\n") + "\n" + bullet + "\n"
+		return os.WriteFile(filePath, []byte(out), 0o644)
 	}
-	return []byte(b.String()), true, nil
+	return os.WriteFile(filePath, []byte(b.String()), 0o644)
 }

ingestion/internal/brain/tunnel_root_test.go

@@ -1,141 +0,0 @@
-package brain_test
-
-import (
-	"os"
-	"path/filepath"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brain"
-)
-
-// brain_tunnel passes caller-supplied source and target paths to WriteTunnel,
-// which checked only "wiki/<wing>/..." and then joined them onto the brain
-// dir: ".." segments resolved outside the brain and appendSeeAlso rewrote the
-// file there.
-func TestWriteTunnelRefusesATargetThatTraversesOutOfTheBrain(t *testing.T) {
-	brain0 := t.TempDir()
-	src := filepath.Join(brain0, "wiki", "a", "facts", "s.md")
-	require.NoError(t, os.MkdirAll(filepath.Dir(src), 0o755))
-	require.NoError(t, os.WriteFile(src, []byte("---\ntitle: S\n---\nbody\n"), 0o644))
-	victim := filepath.Join(t.TempDir(), "victim.md")
-	require.NoError(t, os.WriteFile(victim, []byte("untouched\n"), 0o644))
-
-	up := strings.Repeat("../", strings.Count(filepath.Clean(brain0), "/")+3)
-	target := "wiki/b/x/" + up + strings.TrimPrefix(victim, "/")
-	err := brain.WriteTunnel(brain0, "wiki/a/facts/s.md", target)
-	assert.Error(t, err)
-	got, rerr := os.ReadFile(victim)
-	require.NoError(t, rerr)
-	assert.Equal(t, "untouched\n", string(got), "a file outside the brain was modified")
-}
-
-func TestWriteTunnelRefusesUncleanOrNonWikiPaths(t *testing.T) {
-	brain0 := t.TempDir()
-	for _, p := range []string{"wiki/a/facts/s.md", "wiki/b/facts/t.md", "wiki/b/facts/t.txt", "raw/r.md"} {
-		require.NoError(t, os.MkdirAll(filepath.Dir(filepath.Join(brain0, p)), 0o755))
-		require.NoError(t, os.WriteFile(filepath.Join(brain0, p), []byte("x\n"), 0o644))
-	}
-	for _, target := range []string{
-		"wiki/b/facts/../../../raw/r.md",
-		"wiki/b/./facts/t.md",
-		"wiki/b//facts/t.md",
-		"/wiki/b/facts/t.md",
-		"wiki/b/facts/t.txt",
-		"wiki/b/facts/",
-	} {
-		assert.Error(t, brain.WriteTunnel(brain0, "wiki/a/facts/s.md", target), target)
-	}
-	for _, p := range []string{"raw/r.md", "wiki/b/facts/t.txt"} {
-		got, err := os.ReadFile(filepath.Join(brain0, p))
-		require.NoError(t, err)
-		assert.Equal(t, "x\n", string(got), p)
-	}
-	require.NoError(t, brain.WriteTunnel(brain0, "wiki/a/facts/s.md", "wiki/b/facts/t.md"), "positive control")
-	got, err := os.ReadFile(filepath.Join(brain0, "wiki", "b", "facts", "t.md"))
-	require.NoError(t, err)
-	assert.Contains(t, string(got), "[[a/facts/s]]")
-}
-
-func TestWriteTunnelDoesNotWriteThroughASymlinkedNote(t *testing.T) {
-	brain0 := t.TempDir()
-	src := filepath.Join(brain0, "wiki", "a", "facts", "s.md")
-	require.NoError(t, os.MkdirAll(filepath.Dir(src), 0o755))
-	require.NoError(t, os.WriteFile(src, []byte("x\n"), 0o644))
-	tdir := filepath.Join(brain0, "wiki", "b", "facts")
-	require.NoError(t, os.MkdirAll(tdir, 0o755))
-	victim := filepath.Join(t.TempDir(), "victim.md")
-	require.NoError(t, os.WriteFile(victim, []byte("untouched\n"), 0o644))
-	require.NoError(t, os.Symlink(victim, filepath.Join(tdir, "t.md")))
-	assert.Error(t, brain.WriteTunnel(brain0, "wiki/a/facts/s.md", "wiki/b/facts/t.md"))
-	got, err := os.ReadFile(victim)
-	require.NoError(t, err)
-	assert.Equal(t, "untouched\n", string(got))
-
-	// The same with a link to a file elsewhere in the brain, which os.Root
-	// would follow.
-	inVictim := filepath.Join(brain0, "raw", "v.md")
-	require.NoError(t, os.MkdirAll(filepath.Dir(inVictim), 0o755))
-	require.NoError(t, os.WriteFile(inVictim, []byte("untouched\n"), 0o644))
-	require.NoError(t, os.Symlink(filepath.Join("..", "..", "..", "raw", "v.md"), filepath.Join(tdir, "u.md")))
-	assert.Error(t, brain.WriteTunnel(brain0, "wiki/a/facts/s.md", "wiki/b/facts/u.md"))
-	got, err = os.ReadFile(inVictim)
-	require.NoError(t, err)
-	assert.Equal(t, "untouched\n", string(got))
-	got, err = os.ReadFile(src)
-	require.NoError(t, err)
-	assert.Equal(t, "x\n", string(got), "the source is not touched when the target is refused")
-}
-
-// The target is swapped between a regular note and a symlink to an in-brain
-// file outside wiki/ while WriteTunnel runs: the read and the write each
-// refuse a symlink, so the other file is never rewritten.
-func TestWriteTunnelNeverRewritesASymlinkSwappedInForTheTarget(t *testing.T) {
-	brain0 := t.TempDir()
-	src := filepath.Join(brain0, "wiki", "a", "facts", "s.md")
-	require.NoError(t, os.MkdirAll(filepath.Dir(src), 0o755))
-	require.NoError(t, os.WriteFile(src, []byte("x\n"), 0o644))
-	tdir := filepath.Join(brain0, "wiki", "b", "facts")
-	require.NoError(t, os.MkdirAll(tdir, 0o755))
-	victim := filepath.Join(brain0, "raw", "victim.md")
-	require.NoError(t, os.MkdirAll(filepath.Dir(victim), 0o755))
-	require.NoError(t, os.WriteFile(victim, []byte("untouched\n"), 0o644))
-	tgt := filepath.Join(tdir, "t.md")
-	require.NoError(t, os.WriteFile(tgt, []byte("t\n"), 0o644))
-
-	var stop atomic.Bool
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-		tmp := tgt + ".swap"
-		for i := 0; !stop.Load(); i++ {
-			_ = os.Remove(tmp)
-			if i%2 == 0 {
-				_ = os.WriteFile(tmp, []byte("t\n"), 0o644)
-			} else {
-				_ = os.Symlink(filepath.Join("..", "..", "..", "raw", "victim.md"), tmp)
-			}
-			_ = os.Rename(tmp, tgt)
-		}
-	}()
-	ok := 0
-	for deadline := time.Now().Add(1500 * time.Millisecond); time.Now().Before(deadline); {
-		if brain.WriteTunnel(brain0, "wiki/a/facts/s.md", "wiki/b/facts/t.md") == nil {
-			ok++
-		}
-		_ = os.WriteFile(src, []byte("x\n"), 0o644)
-	}
-	stop.Store(true)
-	wg.Wait()
-	got, err := os.ReadFile(victim)
-	require.NoError(t, err)
-	assert.Equal(t, "untouched\n", string(got), "the swapped-in symlink's target was rewritten")
-	assert.Positive(t, ok, "positive control: some tunnels were written to the regular target")
-}

ingestion/internal/brainfs/brainfs.go

@@ -1,239 +0,0 @@
-// Package brainfs reads the brain directory through an os.Root (hyperguild#157).
-// The brain dir is a Syncthing sendreceive folder and Syncthing syncs
-// symlinks; a reader that walks and reads by path follows a planted symlink
-// out of the brain, and blocks forever on a planted FIFO. Readers that go
-// through a Brain only ever read regular files inside the brain: os.Root
-// refuses to leave the root even if an entry is swapped mid-read, and every
-// open is non-blocking with the type checked on the opened handle.
-package brainfs
-
-import (
-	"errors"
-	"fmt"
-	"io"
-	"io/fs"
-	"os"
-	"path"
-	"path/filepath"
-	"strings"
-	"syscall"
-)
-
-// ErrNotRegular is returned for an entry that is not a regular file.
-var ErrNotRegular = errors.New("not a regular file")
-
-// ErrTooLarge is returned by ReadRegularMax for a file over the limit.
-var ErrTooLarge = errors.New("file too large")
-
-// Brain is an open brain directory.
-type Brain struct {
-	root *os.Root
-	dir  string
-}
-
-// Open opens brainDir (which may itself be a mount symlink) as a root.
-func Open(brainDir string) (*Brain, error) {
-	r, err := os.OpenRoot(brainDir)
-	if err != nil {
-		return nil, fmt.Errorf("open brain root: %w", err)
-	}
-	return &Brain{root: r, dir: brainDir}, nil
-}
-
-// Close releases the root.
-func (b *Brain) Close() error { return b.root.Close() }
-
-// Rel converts a path under the brain dir to a root-relative path.
-func (b *Brain) Rel(path string) (string, error) {
-	rel, err := filepath.Rel(b.dir, path)
-	if err != nil {
-		return "", err
-	}
-	if rel == ".." || len(rel) > 2 && rel[:3] == ".."+string(filepath.Separator) {
-		return "", fmt.Errorf("%s is outside the brain dir", path)
-	}
-	return filepath.ToSlash(rel), nil
-}
-
-// Lstat stats a brain-relative path through the root without following a
-// final symlink.
-func (b *Brain) Lstat(rel string) (fs.FileInfo, error) {
-	return b.root.Lstat(filepath.ToSlash(rel))
-}
-
-// realDir returns ErrNotRegular unless every component of rel is a real
-// directory. A swap after the check is not caught (accepted residual,
-// hyperguild#157).
-func (b *Brain) realDir(rel string) error {
-	if rel == "." {
-		return nil
-	}
-	prefix := ""
-	for _, part := range strings.Split(rel, "/") {
-		prefix = path.Join(prefix, part)
-		fi, err := b.root.Lstat(prefix)
-		if err != nil {
-			return err
-		}
-		if !fi.IsDir() {
-			return fmt.Errorf("%s: walk root component %s is not a directory: %w", rel, prefix, ErrNotRegular)
-		}
-	}
-	return nil
-}
-
-// WriteRegular replaces the contents of an existing regular file at a
-// brain-relative path. It never creates a file and never writes through a
-// final symlink: os.Root.OpenFile follows an in-root final symlink even with
-// O_NOFOLLOW (verified on go1.27), so the path is Lstat-ed through the root
-// first and the opened handle must be that same file (os.SameFile), which
-// also catches a swap between the two. O_NONBLOCK keeps a FIFO from blocking
-// the open. Intermediate in-brain symlinks are still followed (os.Root keeps
-// the write inside the brain; hyperguild#167).
-func (b *Brain) WriteRegular(rel string, data []byte) error {
-	rel = filepath.ToSlash(rel)
-	lfi, err := b.root.Lstat(rel)
-	if err != nil {
-		return err
-	}
-	if !lfi.Mode().IsRegular() {
-		return fmt.Errorf("%s: %w", rel, ErrNotRegular)
-	}
-	f, err := b.root.OpenFile(rel, os.O_WRONLY|syscall.O_NOFOLLOW|syscall.O_NONBLOCK, 0)
-	if err != nil {
-		return err
-	}
-	defer func() { _ = f.Close() }()
-	fi, err := f.Stat()
-	if err != nil {
-		return err
-	}
-	if !fi.Mode().IsRegular() || !os.SameFile(lfi, fi) {
-		return fmt.Errorf("%s: changed while opening: %w", rel, ErrNotRegular)
-	}
-	if err := f.Truncate(0); err != nil {
-		return err
-	}
-	if _, err := f.Write(data); err != nil {
-		return err
-	}
-	return f.Close()
-}
-
-// ReadRegular reads a brain-relative path, refusing anything that is not a
-// regular file, both before the open and on the opened handle.
-func (b *Brain) ReadRegular(rel string) ([]byte, error) {
-	fi, err := b.root.Lstat(rel)
-	if err != nil {
-		return nil, err
-	}
-	if !fi.Mode().IsRegular() {
-		return nil, fmt.Errorf("%s: %w", rel, ErrNotRegular)
-	}
-	return b.readOpened(rel)
-}
-
-// readOpened opens rel non-blocking and reads it only if the OPENED handle is
-// a regular file. This is the check that matters under a race: an entry
-// swapped for a FIFO after the Lstat, with a writer holding it open, would
-// otherwise park io.ReadAll forever (PR #161 review: removing it hung search
-// after 16 iterations).
-//
-// Accepted residual, as in api/rawroot.go: a HARD link to an outside file is
-// a regular file and is read. Syncthing syncs contents, not links, so a peer
-// cannot create one; fs.protected_hardlinks=1 and the pod's secrets are on a
-// different filesystem from the brain volume, so a local caller cannot link
-// them in. Refusing Nlink > 1 is the next step if either changes.
-func (b *Brain) readOpened(rel string) ([]byte, error) { return b.readOpenedMax(rel, -1) }
-
-// ReadRegularMax is ReadRegular with a size limit, checked on the opened
-// handle before reading (max < 0 means no limit).
-func (b *Brain) ReadRegularMax(rel string, max int64) ([]byte, error) {
-	fi, err := b.root.Lstat(rel)
-	if err != nil {
-		return nil, err
-	}
-	if !fi.Mode().IsRegular() {
-		return nil, fmt.Errorf("%s: %w", rel, ErrNotRegular)
-	}
-	return b.readOpenedMax(rel, max)
-}
-
-func (b *Brain) readOpenedMax(rel string, max int64) ([]byte, error) {
-	f, err := b.root.OpenFile(rel, os.O_RDONLY|syscall.O_NONBLOCK, 0)
-	if err != nil {
-		return nil, err
-	}
-	defer func() { _ = f.Close() }()
-	hfi, err := f.Stat()
-	if err != nil {
-		return nil, err
-	}
-	if !hfi.Mode().IsRegular() {
-		return nil, fmt.Errorf("%s: %w", rel, ErrNotRegular)
-	}
-	if max >= 0 && hfi.Size() > max {
-		return nil, fmt.Errorf("%s is %d bytes (limit %d): %w", rel, hfi.Size(), max, ErrTooLarge)
-	}
-	var r io.Reader = f
-	if wrapAfterStat != nil {
-		r = wrapAfterStat(r)
-	}
-	if max < 0 {
-		return io.ReadAll(r)
-	}
-	// The handle's size can grow after the check; bound the read itself.
-	data, err := io.ReadAll(io.LimitReader(r, max+1))
-	if err != nil {
-		return nil, err
-	}
-	if int64(len(data)) > max {
-		return nil, fmt.Errorf("%s grew past %d bytes while read: %w", rel, max, ErrTooLarge)
-	}
-	return data, nil
-}
-
-// wrapAfterStat is a test seam: it runs between the size check and the read,
-// and wraps the reader the read consumes. A package global: brainfs tests
-// must not use t.Parallel.
-var wrapAfterStat func(io.Reader) io.Reader
-
-// WalkRegular walks a brain-relative directory through the root and calls fn
-// for each regular file. Directories are descended; symlinks, FIFOs and
-// devices found by the walk are skipped. A walk root with any component that
-// is not a real directory goes to onErr as ErrNotRegular and nothing is
-// yielded. An entry error is passed to onErr and the walk continues; a nil
-// onErr ignores it.
-//
-// Accepted residual (hyperguild#157): a directory swapped for a symlink
-// between the listing and the read is followed. os.Root still keeps the read
-// inside the brain, but not inside relDir.
-func (b *Brain) WalkRegular(relDir string, fn func(rel string) error, onErr func(rel string, err error)) error {
-	relDir = filepath.ToSlash(relDir)
-	// fs.WalkDir stats its root with a follow, and os.Root allows a symlink
-	// that stays inside the brain: knowledge -> . would alias the whole
-	// brain. Require every component of the root to be a real directory
-	// (Lstat checks only the last one).
-	err := b.realDir(relDir)
-	if err != nil {
-		if onErr != nil {
-			onErr(relDir, err)
-		}
-		return nil
-	}
-	return fs.WalkDir(b.root.FS(), relDir, func(p string, d fs.DirEntry, err error) error {
-		if err != nil {
-			if onErr != nil {
-				onErr(p, err)
-			}
-			if d != nil && d.IsDir() {
-				return fs.SkipDir
-			}
-			return nil
-		}
-		if d.IsDir() || !d.Type().IsRegular() {
-			return nil
-		}
-		return fn(p)
-	})
-}

ingestion/internal/brainfs/brainfs_test.go

@@ -1,237 +0,0 @@
-package brainfs
-
-import (
-	"errors"
-	"io"
-	"io/fs"
-	"os"
-	"path/filepath"
-	"syscall"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// The handle check is what stops a FIFO swapped in after the Lstat. A FIFO
-// with no writer reads EOF at once, so a race test could not see the check
-// missing; here a writer holds the FIFO open, as any local process can, and
-// readOpened must refuse it promptly (PR #161 review).
-func TestReadOpenedRefusesAFIFOHeldOpenByAWriter(t *testing.T) {
-	dir := t.TempDir()
-	fifo := filepath.Join(dir, "p.md")
-	require.NoError(t, syscall.Mkfifo(fifo, 0o644))
-	w, err := os.OpenFile(fifo, os.O_RDWR, 0)
-	require.NoError(t, err)
-	defer func() { _ = w.Close() }()
-
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-
-	done := make(chan error, 1)
-	go func() { _, err := b.readOpened("p.md"); done <- err }()
-	select {
-	case err := <-done:
-		assert.True(t, errors.Is(err, ErrNotRegular), "got %v", err)
-	case <-time.After(2 * time.Second):
-		t.Fatal("readOpened blocked on a FIFO with a writer")
-	}
-}
-
-func TestReadRegularRefusesSymlinksAndReadsRegularFiles(t *testing.T) {
-	dir := t.TempDir()
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "ok.md"), []byte("ok"), 0o644))
-	outside := filepath.Join(t.TempDir(), "s.md")
-	require.NoError(t, os.WriteFile(outside, []byte("secret"), 0o644))
-	require.NoError(t, os.Symlink(outside, filepath.Join(dir, "link.md")))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	got, err := b.ReadRegular("ok.md")
-	require.NoError(t, err)
-	assert.Equal(t, "ok", string(got))
-	_, err = b.ReadRegular("link.md")
-	assert.True(t, errors.Is(err, ErrNotRegular), "got %v", err)
-	_, err = b.ReadRegular("../" + filepath.Base(outside))
-	assert.Error(t, err)
-}
-
-func TestRelAcceptsPathsInsideAndRefusesEscapes(t *testing.T) {
-	dir := t.TempDir()
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	for in, want := range map[string]string{
-		filepath.Join(dir, "wiki", "x.md"): "wiki/x.md",
-		filepath.Join(dir, "..foo", "x"):   "..foo/x",
-		dir:                                ".",
-	} {
-		got, err := b.Rel(in)
-		require.NoError(t, err, in)
-		assert.Equal(t, want, got, in)
-	}
-	for _, bad := range []string{filepath.Join(dir, "..", "x"), dir + "-evil/x", "/etc/passwd", filepath.Join(dir, "wiki", "..", "..", "x")} {
-		_, err := b.Rel(bad)
-		assert.Error(t, err, bad)
-	}
-}
-
-func TestWalkRegularYieldsOnlyRegularFiles(t *testing.T) {
-	dir := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(dir, "a"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "a", "n.md"), []byte("n"), 0o644))
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(dir, "a", "dirlink")))
-	require.NoError(t, os.Symlink(filepath.Join(dir, "a", "n.md"), filepath.Join(dir, "a", "filelink.md")))
-	require.NoError(t, syscall.Mkfifo(filepath.Join(dir, "a", "p.md"), 0o644))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	var got []string
-	require.NoError(t, b.WalkRegular(".", func(rel string) error { got = append(got, rel); return nil }, nil))
-	assert.Equal(t, []string{"a/n.md"}, got)
-}
-
-func TestReadRegularMaxRefusesAFileOverTheLimit(t *testing.T) {
-	dir := t.TempDir()
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "big.md"), make([]byte, 100), 0o644))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	_, err = b.ReadRegularMax("big.md", 99)
-	assert.True(t, errors.Is(err, ErrTooLarge), "got %v", err)
-	got, err := b.ReadRegularMax("big.md", 100)
-	require.NoError(t, err)
-	assert.Len(t, got, 100)
-}
-
-func TestReadRegularMaxRefusesAndStopsReadingAFileThatGrowsPastTheLimit(t *testing.T) {
-	dir := t.TempDir()
-	p := filepath.Join(dir, "grow.md")
-	require.NoError(t, os.WriteFile(p, make([]byte, 10), 0o644))
-	consumed := &countingReader{}
-	wrapAfterStat = func(r io.Reader) io.Reader {
-		f, err := os.OpenFile(p, os.O_WRONLY|os.O_APPEND, 0)
-		require.NoError(t, err)
-		_, err = f.Write(make([]byte, 1000))
-		require.NoError(t, err)
-		require.NoError(t, f.Close())
-		consumed.r = r
-		return consumed
-	}
-	t.Cleanup(func() { wrapAfterStat = nil })
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	got, err := b.ReadRegularMax("grow.md", 100)
-	assert.True(t, errors.Is(err, ErrTooLarge), "got %v", err)
-	assert.Nil(t, got)
-	assert.LessOrEqual(t, consumed.n, 101, "read past max+1 bytes")
-}
-
-type countingReader struct {
-	r io.Reader
-	n int
-}
-
-func (c *countingReader) Read(p []byte) (int, error) {
-	n, err := c.r.Read(p)
-	c.n += n
-	return n, err
-}
-
-func TestLstatDoesNotFollowSymlinksAndRefusesEscapes(t *testing.T) {
-	dir := t.TempDir()
-	outside := filepath.Join(t.TempDir(), "o.md")
-	require.NoError(t, os.WriteFile(outside, []byte("o"), 0o644))
-	require.NoError(t, os.Symlink(outside, filepath.Join(dir, "l.md")))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	fi, err := b.Lstat("l.md")
-	require.NoError(t, err)
-	assert.Equal(t, fs.ModeSymlink, fi.Mode().Type())
-	_, err = b.Lstat("../" + filepath.Base(filepath.Dir(outside)) + "/o.md")
-	assert.Error(t, err)
-}
-
-func TestWalkRegularReportsASymlinkedWalkRootAndYieldsNothing(t *testing.T) {
-	dir := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(dir, "real"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "real", "n.md"), []byte("n"), 0o644))
-	require.NoError(t, os.Symlink("real", filepath.Join(dir, "alias")))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	var got []string
-	var errs []error
-	require.NoError(t, b.WalkRegular("alias", func(rel string) error { got = append(got, rel); return nil },
-		func(_ string, err error) { errs = append(errs, err) }))
-	assert.Empty(t, got)
-	require.Len(t, errs, 1)
-	assert.ErrorIs(t, errs[0], ErrNotRegular)
-}
-
-func TestWalkRegularReportsASymlinkedIntermediateComponentOfTheWalkRoot(t *testing.T) {
-	dir := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(dir, "real", "sub"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "real", "sub", "n.md"), []byte("n"), 0o644))
-	require.NoError(t, os.Symlink("real", filepath.Join(dir, "alias")))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-	var got []string
-	var errs []error
-	require.NoError(t, b.WalkRegular("alias/sub", func(rel string) error { got = append(got, rel); return nil },
-		func(_ string, err error) { errs = append(errs, err) }))
-	assert.Empty(t, got)
-	require.Len(t, errs, 1)
-	assert.ErrorIs(t, errs[0], ErrNotRegular)
-}
-
-func TestWriteRegularRefusesFinalSymlinksFIFOsEscapesAndMissingFilesAndRewritesRegularFiles(t *testing.T) {
-	dir := t.TempDir()
-	outside := filepath.Join(t.TempDir(), "o.md")
-	require.NoError(t, os.WriteFile(outside, []byte("untouched"), 0o644))
-	require.NoError(t, os.Symlink(outside, filepath.Join(dir, "l.md")))
-	require.NoError(t, syscall.Mkfifo(filepath.Join(dir, "f.md"), 0o644))
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "n.md"), []byte("old content"), 0o644))
-	b, err := Open(dir)
-	require.NoError(t, err)
-	defer func() { _ = b.Close() }()
-
-	assert.Error(t, b.WriteRegular("l.md", []byte("x")))
-	got, _ := os.ReadFile(outside)
-	assert.Equal(t, "untouched", string(got))
-
-	// A symlink to another file inside the brain: os.Root would allow it,
-	// only O_NOFOLLOW refuses it.
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "in.md"), []byte("inside"), 0o644))
-	require.NoError(t, os.Symlink("in.md", filepath.Join(dir, "il.md")))
-	assert.Error(t, b.WriteRegular("il.md", []byte("x")))
-	got, _ = os.ReadFile(filepath.Join(dir, "in.md"))
-	assert.Equal(t, "inside", string(got))
-
-	// A reader held open, so a non-blocking write open would succeed. The
-	// Lstat type check refuses the FIFO first; the handle check and
-	// O_NONBLOCK matter only if it is swapped in after the Lstat.
-	r, err := os.OpenFile(filepath.Join(dir, "f.md"), os.O_RDONLY|syscall.O_NONBLOCK, 0)
-	require.NoError(t, err)
-	defer func() { _ = r.Close() }()
-	done := make(chan error, 1)
-	go func() { done <- b.WriteRegular("f.md", []byte("x")) }()
-	select {
-	case err := <-done:
-		assert.Error(t, err)
-	case <-time.After(3 * time.Second):
-		t.Fatal("WriteRegular hung on a FIFO")
-	}
-
-	assert.Error(t, b.WriteRegular("../"+filepath.Base(filepath.Dir(outside))+"/o.md", []byte("x")))
-	assert.Error(t, b.WriteRegular("missing.md", []byte("x")), "does not create files")
-
-	require.NoError(t, b.WriteRegular("n.md", []byte("new")))
-	got, _ = os.ReadFile(filepath.Join(dir, "n.md"))
-	assert.Equal(t, "new", string(got), "truncated and rewritten")
-}

ingestion/internal/brainfs/brainfstest/brainfstest.go

@@ -1,103 +0,0 @@
-// Package brainfstest is the shared harness for hyperguild#157's swap-race
-// tests: it keeps swapping a regular note, a symlink to an outside file, or a
-// FIFO (with a writer held open) into a path while a reader under test loops.
-// It observes two things: no sentinel byte from the outside file reaches the
-// reader's output, and the reader returns within a timeout. It does not cover
-// hard links, other paths into the reader, or races it does not generate.
-package brainfstest
-
-import (
-	"os"
-	"path/filepath"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"syscall"
-	"testing"
-	"time"
-)
-
-// Sentinel marks the outside file's contents.
-const Sentinel = "zqbrainfssentinelonefiftyseven"
-
-// Outside writes a file outside any brain dir containing Sentinel.
-func Outside(t *testing.T) string {
-	t.Helper()
-	p := filepath.Join(t.TempDir(), "secret.md")
-	if err := os.WriteFile(p, []byte("# secret\n\n"+Sentinel), 0o644); err != nil {
-		t.Fatal(err)
-	}
-	return p
-}
-
-// StartSwap renames, in a loop, a regular note (content inside) and either
-// a symlink to outside or a FIFO into path, until the test ends. FIFOs get a
-// writer held open until the swapper exits, so a reader that skips the
-// handle check parks forever instead of reading EOF. The swapper is stopped
-// and awaited before t.TempDir cleanup.
-func StartSwap(t *testing.T, path, inside, outside string, fifo bool) {
-	t.Helper()
-	var stop atomic.Bool
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-		tmp := path + ".swap"
-		var writers []*os.File
-		defer func() {
-			for _, w := range writers {
-				_ = w.Close()
-			}
-		}()
-		for i := 0; !stop.Load(); i++ {
-			_ = os.Remove(tmp)
-			switch {
-			case i%2 == 0:
-				_ = os.WriteFile(tmp, []byte(inside), 0o644)
-			case fifo:
-				if err := syscall.Mkfifo(tmp, 0o644); err == nil {
-					if w, err := os.OpenFile(tmp, os.O_RDWR, 0); err == nil {
-						writers = append(writers, w)
-					}
-				}
-			default:
-				_ = os.Symlink(outside, tmp)
-			}
-			_ = os.Rename(tmp, path)
-		}
-	}()
-	t.Cleanup(func() { stop.Store(true); wg.Wait() })
-}
-
-// AssertNoLeak loops read for d while a symlink swapper runs on path, and
-// fails if any output contains Sentinel.
-func AssertNoLeak(t *testing.T, path, inside string, d time.Duration, read func() string) {
-	t.Helper()
-	StartSwap(t, path, inside, Outside(t), false)
-	leaks, iters := 0, 0
-	for deadline := time.Now().Add(d); time.Now().Before(deadline); iters++ {
-		leaks += strings.Count(read(), Sentinel)
-	}
-	if leaks > 0 {
-		t.Fatalf("outside file leaked %d times in %d iterations", leaks, iters)
-	}
-}
-
-// AssertNoHang loops read for d while a FIFO swapper (held writers) runs on
-// path, and fails if a read does not return within timeout.
-func AssertNoHang(t *testing.T, path, inside string, d, timeout time.Duration, read func()) {
-	t.Helper()
-	StartSwap(t, path, inside, Outside(t), true)
-	done := make(chan struct{})
-	go func() {
-		for deadline := time.Now().Add(d); time.Now().Before(deadline); {
-			read()
-		}
-		close(done)
-	}()
-	select {
-	case <-done:
-	case <-time.After(timeout):
-		t.Fatal("reader hung on a swapped-in FIFO with a writer held open")
-	}
-}

ingestion/internal/extract/callsites_test.go

@@ -1,130 +0,0 @@
-package extract
-
-import (
-	"go/ast"
-	"go/parser"
-	"go/token"
-	"os"
-	"path/filepath"
-	"strconv"
-	"strings"
-	"testing"
-)
-
-const extractPkg = "github.com/mathiasbq/hyperguild/ingestion/internal/extract"
-
-// parseNonTest parses every non-test Go file under the module.
-func parseNonTest(t *testing.T) map[string]*ast.File {
-	t.Helper()
-	fset := token.NewFileSet()
-	out := map[string]*ast.File{}
-	err := filepath.WalkDir(filepath.Join("..", ".."), func(p string, d os.DirEntry, err error) error {
-		if err != nil {
-			return err
-		}
-		if d.IsDir() && (d.Name() == "vendor" || d.Name() == ".git") {
-			return filepath.SkipDir
-		}
-		if d.IsDir() || !strings.HasSuffix(p, ".go") || strings.HasSuffix(p, "_test.go") {
-			return nil
-		}
-		f, perr := parser.ParseFile(fset, p, nil, 0)
-		if perr != nil {
-			return perr
-		}
-		out[filepath.ToSlash(p)] = f
-		return nil
-	})
-	if err != nil {
-		t.Fatal(err)
-	}
-	return out
-}
-
-// PR #156 review: reading a caller-chosen path by name reopens it after the
-// containment check (hyperguild#153 item 3). Outside this package, nothing
-// may reference extract.Text — called OR taken as a value — under whatever
-// name the package is imported (round 2: an alias and a func value slipped
-// past a plain text search).
-func TestNoPackageReferencesExtractTextOutsideExtract(t *testing.T) {
-	for path, f := range parseNonTest(t) {
-		if strings.Contains(path, "internal/extract/") {
-			continue
-		}
-		names := map[string]bool{}
-		for _, imp := range f.Imports {
-			if p, _ := strconv.Unquote(imp.Path.Value); p == extractPkg {
-				name := "extract"
-				if imp.Name != nil {
-					name = imp.Name.Name
-				}
-				if name == "." {
-					t.Errorf("%s dot-imports extract; import it by name so its use stays checkable", path)
-				}
-				names[name] = true
-			}
-		}
-		if len(names) == 0 {
-			continue
-		}
-		ast.Inspect(f, func(n ast.Node) bool {
-			if sel, ok := n.(*ast.SelectorExpr); ok {
-				if id, ok := sel.X.(*ast.Ident); ok && names[id.Name] && sel.Sel.Name == "Text" {
-					t.Errorf("%s references %s.Text; use extract.TextIn through an os.Root", path, id.Name)
-				}
-			}
-			return true
-		})
-	}
-}
-
-// PR #156 review round 2: the FIFO fix (open non-blocking, check the handle)
-// lives in OpenRegular, and reverting any caller to a plain Root.Open stayed
-// green. In the three raw/ reader FILES parsed below (and only those: a
-// wrapper in another file is not seen), no Open/OpenFile/ReadFile selector
-// may appear outside OpenRegular, called or taken as a method value. This is
-// a second layer; the behavioural race tests in internal/api and
-// internal/watcher are what catch a rewrite through any API (round 3).
-// osOpenAllowed names the functions in guarded files that may call os.Open*
-// on a path that is not a raw/ read.
-var osOpenAllowed = map[string]bool{
-	"internal/watcher/watcher.go:appendWatcherLog": true, // ingest log append, not a raw/ read
-	// Text reads by path; outside this package only TextIn's temp copy reaches
-	// it (TestNoPackageReferencesExtractTextOutsideExtract enforces that).
-	"internal/extract/extract.go:Text": true,
-}
-
-func TestRawReaderFilesUseNoOpenOrReadFileOutsideOpenRegular(t *testing.T) {
-	guarded := []string{"internal/api/rawroot.go", "internal/extract/extract.go", "internal/watcher/watcher.go"}
-	files := parseNonTest(t)
-	for _, g := range guarded {
-		var f *ast.File
-		for p, af := range files {
-			if strings.HasSuffix(p, g) {
-				f = af
-			}
-		}
-		if f == nil {
-			t.Fatalf("guarded file %s not found", g)
-		}
-		for _, decl := range f.Decls {
-			fn, ok := decl.(*ast.FuncDecl)
-			if !ok || fn.Name.Name == "OpenRegular" {
-				continue
-			}
-			ast.Inspect(fn, func(n ast.Node) bool {
-				sel, ok := n.(*ast.SelectorExpr)
-				if !ok {
-					return true
-				}
-				if sel.Sel.Name == "Open" || sel.Sel.Name == "OpenFile" || sel.Sel.Name == "ReadFile" {
-					if id, ok := sel.X.(*ast.Ident); ok && id.Name == "os" && osOpenAllowed[g+":"+fn.Name.Name] {
-						return true // a named non-raw write (the ingest log append)
-					}
-					t.Errorf("%s: %s calls .%s; raw/ reads must go through OpenRegular", g, fn.Name.Name, sel.Sel.Name)
-				}
-				return true
-			})
-		}
-	}
-}

ingestion/internal/extract/extract.go

@@ -3,10 +3,8 @@ package extract
 
 import (
 	"fmt"
-	"io"
 	"os"
 	"strings"
-	"syscall"
 )
 
 // Text reads the file at path and returns its plain-text content.
@@ -43,70 +41,3 @@ func fileExt(path string) string {
 	}
 	return ""
 }
-
-// TextIn is Text for a file read through an os.Root (hyperguild#153): the
-// read cannot leave the root, so a path checked earlier cannot be swapped
-// for a symlink pointing elsewhere before it is read. Formats that need an
-// external tool (pdf, docmark) are copied to a temp file from the handle
-// opened through the root, then extracted from the copy.
-func TextIn(r *os.Root, rel string) (string, error) {
-	fi, err := r.Lstat(rel)
-	if err != nil {
-		return "", fmt.Errorf("stat %s: %w", rel, err)
-	}
-	if !fi.Mode().IsRegular() {
-		return "", fmt.Errorf("%s: not a regular file", rel)
-	}
-	f, _, err := OpenRegular(r, rel)
-	if err != nil {
-		return "", fmt.Errorf("open %s: %w", rel, err)
-	}
-	defer func() { _ = f.Close() }()
-	ext := strings.ToLower(fileExt(rel))
-	switch ext {
-	case ".md", ".txt":
-		b, err := io.ReadAll(f)
-		if err != nil {
-			return "", fmt.Errorf("read %s: %w", rel, err)
-		}
-		return string(b), nil
-	case ".pdf", ".docx", ".xlsx", ".pptx", ".png", ".jpg", ".jpeg":
-		tmp, err := os.CreateTemp("", "ingest-*"+ext)
-		if err != nil {
-			return "", fmt.Errorf("temp copy: %w", err)
-		}
-		defer func() { _ = os.Remove(tmp.Name()) }()
-		if _, err := io.Copy(tmp, f); err != nil {
-			_ = tmp.Close()
-			return "", fmt.Errorf("copy %s: %w", rel, err)
-		}
-		if err := tmp.Close(); err != nil {
-			return "", fmt.Errorf("copy %s: %w", rel, err)
-		}
-		return Text(tmp.Name())
-	default:
-		return "", fmt.Errorf("unsupported file extension: %s", ext)
-	}
-}
-
-// OpenRegular opens rel inside r and returns it only if the OPENED handle is
-// a regular file. The open is non-blocking, so a FIFO swapped in after an
-// Lstat (PR #156 review: it hung open(2) forever) is refused promptly rather
-// than stalling the reader. Callers keep their Lstat check, which refuses
-// symlinks outright; this closes the race between that check and the open.
-func OpenRegular(r *os.Root, rel string) (*os.File, os.FileInfo, error) {
-	f, err := r.OpenFile(rel, os.O_RDONLY|syscall.O_NONBLOCK, 0)
-	if err != nil {
-		return nil, nil, err
-	}
-	fi, err := f.Stat()
-	if err != nil {
-		_ = f.Close()
-		return nil, nil, err
-	}
-	if !fi.Mode().IsRegular() {
-		_ = f.Close()
-		return nil, nil, fmt.Errorf("%s: not a regular file", rel)
-	}
-	return f, fi, nil
-}

ingestion/internal/extract/root_test.go

@@ -1,64 +0,0 @@
-package extract
-
-import (
-	"os"
-	"path/filepath"
-	"syscall"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// hyperguild#153 item 3: ingest checked a path, then extract.Text reopened it
-// by name, so a file swapped for a symlink in between was followed out of
-// raw/. TextIn reads through an os.Root, which refuses to leave the root.
-func TestTextInReadsInsideTheRootAndRefusesEscapes(t *testing.T) {
-	root := t.TempDir()
-	require.NoError(t, os.WriteFile(filepath.Join(root, "ok.md"), []byte("inside"), 0o644))
-	outside := filepath.Join(t.TempDir(), "secret.md")
-	require.NoError(t, os.WriteFile(outside, []byte("SENTINEL-153-TEXTIN"), 0o644))
-	require.NoError(t, os.Symlink(outside, filepath.Join(root, "leak.md")))
-
-	r, err := os.OpenRoot(root)
-	require.NoError(t, err)
-	defer func() { _ = r.Close() }()
-
-	got, err := TextIn(r, "ok.md")
-	require.NoError(t, err)
-	assert.Equal(t, "inside", got)
-
-	got, err = TextIn(r, "leak.md")
-	assert.Error(t, err)
-	assert.NotContains(t, got, "SENTINEL-153-TEXTIN")
-
-	_, err = TextIn(r, "../"+filepath.Base(outside))
-	assert.Error(t, err)
-}
-
-// PR #156 review: a regular file swapped for a FIFO between Lstat and Open
-// blocked open(2) forever. OpenRegular opens non-blocking and checks the type
-// on the opened handle, so a FIFO is refused promptly instead of hanging.
-func TestOpenRegularRefusesAFIFOWithoutBlocking(t *testing.T) {
-	dir := t.TempDir()
-	require.NoError(t, syscall.Mkfifo(filepath.Join(dir, "pipe.md"), 0o644))
-	r, err := os.OpenRoot(dir)
-	require.NoError(t, err)
-	defer func() { _ = r.Close() }()
-
-	done := make(chan error, 1)
-	go func() {
-		f, _, err := OpenRegular(r, "pipe.md")
-		if f != nil {
-			_ = f.Close()
-		}
-		done <- err
-	}()
-	select {
-	case err := <-done:
-		assert.Error(t, err)
-	case <-time.After(2 * time.Second):
-		t.Fatal("OpenRegular blocked on a FIFO")
-	}
-}

ingestion/internal/mcp/handlers.go

@@ -12,6 +12,7 @@ import (
 	"github.com/mathiasbq/hyperguild/ingestion/internal/api"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/brain"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/capture"
+	"github.com/mathiasbq/hyperguild/ingestion/internal/extract"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/graphsync"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/notes"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/pipeline"
@@ -548,7 +549,7 @@ func (s *Server) brainIngest(ctx context.Context, args json.RawMessage) (json.Ra
 			return nil, err
 		}
 		a.Path = resolved
-		text, err := api.ReadIngestFile(s.brainDir, a.Path)
+		text, err := extract.Text(a.Path)
 		if err != nil {
 			return nil, fmt.Errorf("extract: %w", err)
 		}

ingestion/internal/mcp/readexcerpt_root_test.go

@@ -1,34 +0,0 @@
-package mcp
-
-import (
-	"os"
-	"path/filepath"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs/brainfstest"
-)
-
-// hyperguild#157 slice 2: readExcerpt (brain_context) read by path, so a
-// symlink in the Syncthing-shared brain put an outside file in context, and
-// a FIFO hung it. It now reads through brainfs.
-func TestReadExcerptRefusesSymlinksAndSurvivesSwapRaces(t *testing.T) {
-	brain := t.TempDir()
-	facts := filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(facts, "leak.md")))
-	assert.NotContains(t, readExcerpt(brain, "wiki/w/facts/leak.md", 500), brainfstest.Sentinel)
-
-	p := filepath.Join(facts, "r.md")
-	require.NoError(t, os.WriteFile(p, []byte("---\nx: y\n---\ninside"), 0o644))
-	assert.Equal(t, "inside", readExcerpt(brain, "wiki/w/facts/r.md", 500))
-	brainfstest.AssertNoLeak(t, p, "---\nx: y\n---\ninside", 1500*time.Millisecond, func() string {
-		return readExcerpt(brain, "wiki/w/facts/r.md", 500)
-	})
-	brainfstest.AssertNoHang(t, p, "---\nx: y\n---\ninside", 1500*time.Millisecond, 6*time.Second, func() {
-		_ = readExcerpt(brain, "wiki/w/facts/r.md", 500)
-	})
-}

ingestion/internal/mcp/tools_context.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
+	"os"
 	"path/filepath"
 	"sort"
 	"strings"
@@ -181,13 +181,8 @@ func readExcerpt(brainDir, relPath string, maxLen int) string {
 	if relPath == "" {
 		return ""
 	}
-	// Through the brain root, regular files only (hyperguild#157).
+	full := filepath.Join(brainDir, filepath.FromSlash(relPath))
-	bfs, err := brainfs.Open(brainDir)
+	content, err := os.ReadFile(full)
-	if err != nil {
-		return ""
-	}
-	defer func() { _ = bfs.Close() }()
-	content, err := bfs.ReadRegular(filepath.ToSlash(relPath))
 	if err != nil {
 		return ""
 	}

ingestion/internal/notes/edit.go

@@ -5,7 +5,6 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
 	"os"
 	"path/filepath"
 	"strings"
@@ -72,18 +71,14 @@ func ReadScoped(brainDir, path string, scope Scope) ([]byte, error) {
 }
 
 func readContained(t Target) ([]byte, error) {
-	// Through the brain root, regular files only, size checked on the opened
+	fi, err := os.Stat(t.Abs)
-	// handle (hyperguild#157): Resolve's Lstat could be raced by a swap, and
-	// os.ReadFile blocked on a FIFO.
-	bfs, err := brainfs.Open(t.Brain)
 	if err != nil {
-		return nil, fmt.Errorf("notes: %w", err)
+		return nil, fmt.Errorf("notes: stat %s: %w", t.Rel, err)
 	}
-	defer func() { _ = bfs.Close() }()
+	if fi.Size() > maxNoteBytes {
-	b, err := bfs.ReadRegularMax(t.Rel, maxNoteBytes)
+		return nil, fmt.Errorf("%w: %s is %d bytes (limit %d)", ErrTooLarge, t.Rel, fi.Size(), maxNoteBytes)
-	if errors.Is(err, brainfs.ErrTooLarge) {
-		return nil, fmt.Errorf("%w: %s (limit %d)", ErrTooLarge, t.Rel, maxNoteBytes)
 	}
+	b, err := os.ReadFile(t.Abs)
 	if err != nil {
 		return nil, fmt.Errorf("notes: read %s: %w", t.Rel, err)
 	}

ingestion/internal/notes/path.go

@@ -60,7 +60,6 @@ var (
 type Target struct {
 	Rel string // brain-relative, cleaned
 	Abs string // absolute, symlink-checked
-	Brain string // the brain root Rel is relative to
 }
 
 // Resolve canonicalises path, then checks it against the scope's allowlist,
@@ -110,7 +109,7 @@ func Resolve(brainDir, path string, scope Scope) (Target, error) {
 		return Target{}, err
 	}
 
-	return Target{Rel: clean, Abs: abs, Brain: brainDir}, nil
+	return Target{Rel: clean, Abs: abs}, nil
 }
 
 // allow enforces the scope's allowlist. The two scopes are DISJOINT, not

ingestion/internal/notes/read_root_test.go

@@ -1,40 +0,0 @@
-package notes
-
-import (
-	"os"
-	"path/filepath"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs/brainfstest"
-)
-
-// hyperguild#157 slice 2: ReadScoped (brain_read) Lstat-checked the final
-// component, then reopened by name with os.ReadFile: a swap after the check
-// was followed, and a FIFO blocked the read. It now reads through brainfs.
-func TestReadScopedRefusesSymlinksAndSurvivesSwapRaces(t *testing.T) {
-	brain := t.TempDir()
-	facts := filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	p := filepath.Join(facts, "r.md")
-	read := func() string {
-		b, _ := ReadScoped(brain, "wiki/w/facts/r.md", ScopeNotes)
-		return string(b)
-	}
-	require.NoError(t, os.WriteFile(p, []byte("inside"), 0o644))
-	assert.Equal(t, "inside", read())
-	brainfstest.AssertNoLeak(t, p, "inside", 1500*time.Millisecond, read)
-	brainfstest.AssertNoHang(t, p, "inside", 1500*time.Millisecond, 6*time.Second, func() { _ = read() })
-}
-
-func TestReadScopedRefusesANoteOverMaxNoteBytes(t *testing.T) {
-	brain := t.TempDir()
-	facts := filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(facts, "big.md"), make([]byte, maxNoteBytes+1), 0o644))
-	_, err := ReadScoped(brain, "wiki/w/facts/big.md", ScopeNotes)
-	assert.ErrorIs(t, err, ErrTooLarge)
-}

ingestion/internal/search/brainroot_test.go

@@ -1,174 +0,0 @@
-package search
-
-import (
-	"os"
-	"path/filepath"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"syscall"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// hyperguild#157 option 1: search walked and read the brain by path, so a
-// symlink anywhere in the Syncthing-shared brain dir (wiki/<w>/<h>/leak.md ->
-// /any/file) put the target's contents in brain_query results (reproduced in
-// the PR #156 review). Search now walks and reads through an os.Root on the
-// brain dir and only reads regular files.
-
-const sentinel157 = "zqsentinelonefiftyseven"
-
-func searchBrain(t *testing.T) (brain, facts, outside string) {
-	t.Helper()
-	brain = t.TempDir()
-	facts = filepath.Join(brain, "wiki", "w", "facts")
-	require.NoError(t, os.MkdirAll(facts, 0o755))
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "knowledge"), 0o755))
-	outside = filepath.Join(t.TempDir(), "secret.md")
-	require.NoError(t, os.WriteFile(outside, []byte("# secret\n\n"+sentinel157), 0o644))
-	return brain, facts, outside
-}
-
-func leaked(rs []Result) int {
-	n := 0
-	for _, r := range rs {
-		n += strings.Count(r.Excerpt+r.Title, sentinel157)
-	}
-	return n
-}
-
-func TestQueryDoesNotFollowASymlinkInTheWiki(t *testing.T) {
-	brain, facts, outside := searchBrain(t)
-	require.NoError(t, os.Symlink(outside, filepath.Join(facts, "leak.md")))
-	require.NoError(t, os.WriteFile(filepath.Join(facts, "real.md"), []byte("# real\n\nzqrealnote"), 0o644))
-	rs, err := Query(brain, QueryOptions{Query: sentinel157, Limit: 10})
-	require.NoError(t, err)
-	assert.Zero(t, leaked(rs))
-	rs, err = Query(brain, QueryOptions{Query: "zqrealnote", Limit: 10})
-	require.NoError(t, err)
-	assert.Len(t, rs, 1, "regular notes are still found")
-}
-
-func TestQueryDoesNotFollowASymlinkedDirectory(t *testing.T) {
-	brain, _, outside := searchBrain(t)
-	require.NoError(t, os.Symlink(filepath.Dir(outside), filepath.Join(brain, "wiki", "linked")))
-	rs, err := Query(brain, QueryOptions{Query: sentinel157, Limit: 10})
-	require.NoError(t, err)
-	assert.Zero(t, leaked(rs))
-}
-
-// A search root that is a symlink staying inside the brain (wiki/<w> -> ..)
-// was followed by fs.WalkDir, aliasing raw/ and root files into results
-// (PR #166 review). The root is now Lstat-checked and skipped.
-func TestQueryDoesNotFollowASymlinkedWingRootInsideTheBrain(t *testing.T) {
-	brain, _, _ := searchBrain(t)
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "raw"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(brain, "raw", "r.md"), []byte("# r\n\nzqrawonly"), 0o644))
-	require.NoError(t, os.Symlink("..", filepath.Join(brain, "wiki", "alias")))
-	rs, err := Query(brain, QueryOptions{Query: "zqrawonly", Wing: "alias", Limit: 10})
-	require.NoError(t, err)
-	assert.Empty(t, rs)
-}
-
-// With a hall the search root is wiki/<wing>/<hall>; a symlinked <wing> with
-// a real <hall> directory under its target was followed (PR #166 round 2).
-func TestQueryDoesNotFollowASymlinkedWingUnderAWingAndHallRoot(t *testing.T) {
-	brain, _, _ := searchBrain(t)
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "raw", "facts"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(brain, "raw", "facts", "r.md"), []byte("# r\n\nzqrawhall"), 0o644))
-	require.NoError(t, os.Symlink(filepath.Join("..", "raw"), filepath.Join(brain, "wiki", "alias")))
-	rs, err := Query(brain, QueryOptions{Query: "zqrawhall", Wing: "alias", Hall: "facts", Limit: 10})
-	require.NoError(t, err)
-	assert.Empty(t, rs)
-}
-
-// swapInto keeps renaming a regular note, and either a symlink to outside or
-// a FIFO, into path. Each FIFO has a writer held open (as any local process
-// can): a FIFO with no writer reads EOF at once, which would let a reader
-// that skips the handle check pass (PR #161 round 2: with a held writer, a
-// bypass of readOpened hung Query after 5 iterations).
-// startSwap runs swapInto until the test ends and waits for it before
-// t.TempDir's cleanup (hyperguild#162).
-func startSwap(t *testing.T, path, outside string, fifo bool) {
-	t.Helper()
-	var stop atomic.Bool
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() { defer wg.Done(); swapInto(path, outside, fifo, &stop) }()
-	t.Cleanup(func() { stop.Store(true); wg.Wait() })
-}
-
-func swapInto(path, outside string, fifo bool, stop *atomic.Bool) {
-	tmp := path + ".swap"
-	// Writers stay open until the swapper exits, so a reader parked on a
-	// FIFO stays parked (closing one would hand the reader EOF and hide the
-	// hang). Past the fd limit, new FIFOs simply have no writer.
-	var writers []*os.File
-	defer func() {
-		for _, w := range writers {
-			_ = w.Close()
-		}
-	}()
-	for i := 0; !stop.Load(); i++ {
-		_ = os.Remove(tmp)
-		switch {
-		case i%2 == 0:
-			_ = os.WriteFile(tmp, []byte("# r\n\nzqinside "+"zqracenote"), 0o644)
-		case fifo:
-			if err := syscall.Mkfifo(tmp, 0o644); err == nil {
-				if w, err := os.OpenFile(tmp, os.O_RDWR, 0); err == nil {
-					writers = append(writers, w)
-				}
-			}
-		default:
-			_ = os.Symlink(outside, tmp)
-		}
-		_ = os.Rename(tmp, path)
-	}
-}
-
-func TestQueryLeaksNothingUnderASymlinkSwapRace(t *testing.T) {
-	brain, facts, outside := searchBrain(t)
-	startSwap(t, filepath.Join(facts, "r.md"), outside, false)
-	leaks, iters := 0, 0
-	for deadline := time.Now().Add(1500 * time.Millisecond); time.Now().Before(deadline); iters++ {
-		rs, _ := Query(brain, QueryOptions{Query: sentinel157, Limit: 10})
-		leaks += leaked(rs)
-	}
-	if leaks > 0 {
-		t.Fatalf("outside file leaked %d times in %d iterations", leaks, iters)
-	}
-}
-
-func TestQueryDoesNotHangUnderAFIFOSwapRace(t *testing.T) {
-	brain, facts, outside := searchBrain(t)
-	startSwap(t, filepath.Join(facts, "r.md"), outside, true)
-	done := make(chan struct{})
-	go func() {
-		for deadline := time.Now().Add(1500 * time.Millisecond); time.Now().Before(deadline); {
-			_, _ = Query(brain, QueryOptions{Query: "zqracenote", Limit: 10})
-		}
-		close(done)
-	}()
-	select {
-	case <-done:
-	case <-time.After(6 * time.Second):
-		if f, err := os.OpenFile(filepath.Join(facts, "r.md"), os.O_WRONLY|syscall.O_NONBLOCK, 0); err == nil {
-			_ = f.Close()
-		}
-		t.Fatal("search hung on a swapped-in FIFO")
-	}
-}
-
-// hydrate (vector-only hits) reads by relative path; it must refuse a symlink.
-func TestHydrateRefusesASymlink(t *testing.T) {
-	brain, facts, outside := searchBrain(t)
-	require.NoError(t, os.Symlink(outside, filepath.Join(facts, "leak.md")))
-	r, err := hydrate(brain, "wiki/w/facts/leak.md")
-	assert.Error(t, err)
-	assert.NotContains(t, r.Excerpt, sentinel157)
-}

ingestion/internal/search/search.go

@@ -5,7 +5,6 @@ import (
 	"bufio"
 	"context"
 	"fmt"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
 	sharedfm "github.com/mathiasbq/hyperguild/ingestion/internal/frontmatter"
 	"log/slog"
 	"os"
@@ -120,30 +119,20 @@ func QueryContext(ctx context.Context, brainDir string, opts QueryOptions) ([]Re
 		return nil, err
 	}
 
-	// Walk and read through an os.Root on the brain dir, regular files only
-	// (hyperguild#157): a symlink planted in the Syncthing-shared brain must
-	// not put an outside file in results, nor a FIFO hang the query.
-	bfs, err := brainfs.Open(brainDir)
-	if err != nil {
-		return nil, fmt.Errorf("search: %w", err)
-	}
-	defer func() { _ = bfs.Close() }()
-
 	var results []Result
 	for _, dir := range roots {
 		if _, statErr := os.Stat(dir); os.IsNotExist(statErr) {
 			continue
 		}
-		relDir, relErr := bfs.Rel(dir)
+		err := filepath.WalkDir(dir, func(path string, d os.DirEntry, err error) error {
-		if relErr != nil {
+			if err != nil {
-			return nil, fmt.Errorf("search: %w", relErr)
+				slog.Warn("search: skipping path", "path", path, "err", err)
-		}
-		err := bfs.WalkRegular(relDir, func(relPath string) error {
-			if !strings.HasSuffix(relPath, ".md") {
 				return nil
 			}
-			path := filepath.Join(brainDir, filepath.FromSlash(relPath))
+			if d.IsDir() || !strings.HasSuffix(path, ".md") {
-			content, err := bfs.ReadRegular(relPath)
+				return nil
+			}
+			content, err := os.ReadFile(path)
 			if err != nil {
 				slog.Warn("search: skipping unreadable file", "path", path, "err", err)
 				return nil
@@ -166,7 +155,7 @@ func QueryContext(ctx context.Context, brainDir string, opts QueryOptions) ([]Re
 			origin, writtenBy := extractProvenance(string(content))
 			results = append(results, Result{
 				Path:    rel,
-				Title:   extractTitle(string(content), filepath.Base(relPath)),
+				Title:   extractTitle(string(content), d.Name()),
 				Excerpt: excerpt(string(content), 300),
 				Score:   score,
 				Wing:    wing,
@@ -177,8 +166,6 @@ func QueryContext(ctx context.Context, brainDir string, opts QueryOptions) ([]Re
 				WrittenBy: writtenBy,
 			})
 			return nil
-		}, func(p string, err error) {
-			slog.Warn("search: skipping path", "path", p, "err", err)
 		})
 		if err != nil {
 			return nil, err
@@ -288,13 +275,8 @@ func pathInScope(relPath, wing, hall string) bool {
 // excerpt, wing, and hall populated. Used for paths that surface only
 // via vector search.
 func hydrate(brainDir, relPath string) (Result, error) {
-	// Through the brain root, regular files only (hyperguild#157).
+	full := filepath.Join(brainDir, filepath.FromSlash(relPath))
-	bfs, err := brainfs.Open(brainDir)
+	content, err := os.ReadFile(full)
-	if err != nil {
-		return Result{}, err
-	}
-	defer func() { _ = bfs.Close() }()
-	content, err := bfs.ReadRegular(filepath.ToSlash(relPath))
 	if err != nil {
 		return Result{}, err
 	}

ingestion/internal/session/id_test.go

@@ -1,49 +0,0 @@
-package session
-
-import (
-	"os"
-	"path/filepath"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// session_log passed the caller's session_id straight into
-// filepath.Join(sessionsDir, id+".jsonl") and opened it O_CREATE|O_APPEND:
-// path segments in the id created or appended files anywhere the pod could
-// write. The id is now a plain name, and the open does not follow a final
-// symlink.
-func TestAppendRefusesSessionIDsThatAreNotPlainNames(t *testing.T) {
-	root := t.TempDir()
-	dir := filepath.Join(root, "sessions")
-	for _, id := range []string{"../x", "a/b", "/abs", ".", "..", ".hidden", "", "a\\b", "a\x00b"} {
-		assert.Error(t, Append(dir, id, Entry{SessionID: id}), "%q", id)
-	}
-	ents, _ := os.ReadDir(root)
-	for _, e := range ents {
-		assert.Equal(t, "sessions", e.Name(), "nothing created beside the sessions dir")
-	}
-	for _, id := range []string{"1557b2e1-bf0d-5c4f-bbe3-0754d087e356", "_routing", "2026-05-05-infra.plan", "0"} {
-		require.NoError(t, Append(dir, id, Entry{SessionID: id}), "positive control: %q", id)
-	}
-}
-
-func TestAppendDoesNotWriteThroughASymlinkedLog(t *testing.T) {
-	root := t.TempDir()
-	dir := filepath.Join(root, "sessions")
-	require.NoError(t, os.MkdirAll(dir, 0o755))
-	victim := filepath.Join(root, "victim.md")
-	require.NoError(t, os.WriteFile(victim, []byte("untouched\n"), 0o644))
-	require.NoError(t, os.Symlink(filepath.Join("..", "victim.md"), filepath.Join(dir, "s.jsonl")))
-	assert.Error(t, Append(dir, "s", Entry{SessionID: "s"}))
-	got, _ := os.ReadFile(victim)
-	assert.Equal(t, "untouched\n", string(got))
-}
-
-func TestReadRefusesSessionIDsThatAreNotPlainNames(t *testing.T) {
-	root := t.TempDir()
-	require.NoError(t, os.WriteFile(filepath.Join(root, "x.jsonl"), []byte(`{"session_id":"x"}`+"\n"), 0o644))
-	_, err := Read(filepath.Join(root, "sessions"), "../x")
-	assert.Error(t, err)
-}

ingestion/internal/session/session.go

@@ -9,8 +9,6 @@ import (
 	"io/fs"
 	"os"
 	"path/filepath"
-	"regexp"
-	"syscall"
 	"time"
 )
 
@@ -44,29 +42,13 @@ type Attempt struct {
 	RunnerOutput  string `json:"runner_output,omitempty"`
 }
 
-// idPattern is a plain file name: session_log takes the id from the caller,
-// and a path segment in it created or appended files anywhere the pod could
-// write (hyperguild#169).
-var idPattern = regexp.MustCompile(`^[A-Za-z0-9_][A-Za-z0-9._-]{0,127}$`)
-
-func checkID(sessionID string) error {
-	if !idPattern.MatchString(sessionID) {
-		return fmt.Errorf("session id %q is not a plain name", sessionID)
-	}
-	return nil
-}
-
 // Append writes entry as a single JSON line to sessionsDir/{sessionID}.jsonl.
-// The open does not follow a final symlink.
 func Append(sessionsDir, sessionID string, entry Entry) error {
-	if err := checkID(sessionID); err != nil {
-		return err
-	}
 	if err := os.MkdirAll(sessionsDir, 0o755); err != nil {
 		return fmt.Errorf("create sessions dir: %w", err)
 	}
 	path := filepath.Join(sessionsDir, sessionID+".jsonl")
-	f, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY|syscall.O_NOFOLLOW|syscall.O_NONBLOCK, 0o644)
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o644)
 	if err != nil {
 		return fmt.Errorf("open session log: %w", err)
 	}
@@ -88,9 +70,6 @@ func Append(sessionsDir, sessionID string, entry Entry) error {
 
 // Read returns all entries for sessionID. Returns empty slice if no log exists.
 func Read(sessionsDir, sessionID string) ([]Entry, error) {
-	if err := checkID(sessionID); err != nil {
-		return nil, err
-	}
 	path := filepath.Join(sessionsDir, sessionID+".jsonl")
 	f, err := os.Open(path)
 	if errors.Is(err, fs.ErrNotExist) {

ingestion/internal/symlinkguard/symlinkguard.go

@@ -1,264 +0,0 @@
-// Package symlinkguard is the hyperguild#157 tripwire. The brain directory is
-// a Syncthing sendreceive folder and Syncthing syncs symlinks; several brain
-// readers (search, vectorstore, context, graph) follow a symlink out of the
-// brain and would index or return whatever it points to. Until every reader
-// reads through an os.Root, a symlink inside the brain, or a directory the
-// scan cannot read (which could hide one), is an incident: the server refuses
-// to start on one (main), and Watch reports one that appears while it runs.
-package symlinkguard
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"io/fs"
-	"log/slog"
-	"os"
-	"path/filepath"
-	"sort"
-	"strconv"
-	"strings"
-	"time"
-)
-
-// DefaultInterval is used when Watch is given a non-positive interval.
-const DefaultInterval = 30 * time.Second
-
-// Alert bounds (PR #160 review): the planter chooses the paths, so neither an
-// alert's size nor the queue may grow with what was planted.
-const (
-	maxPathsPerAlert = 10 // further paths are counted, not listed
-	maxPending       = 5  // queued alerts; the rest become one summary
-)
-
-// Notifier is the out-of-band alert sink (audit.Notifier satisfies it).
-type Notifier interface {
-	Notify(ctx context.Context, msg string) error
-}
-
-// Result is what a scan found: symlinks, and directories it could not read
-// (each of which could hide a symlink). Paths are brain-relative.
-type Result struct {
-	Symlinks   []string
-	Unreadable []string
-}
-
-// Clean reports whether the scan found nothing to act on.
-func (r Result) Clean() bool { return len(r.Symlinks) == 0 && len(r.Unreadable) == 0 }
-
-// String describes the findings for a log line or alert. Paths are quoted, so
-// a name containing a newline cannot blur two findings together.
-func (r Result) String() string {
-	q := r.quoted
-	var parts []string
-	if len(r.Symlinks) > 0 {
-		parts = append(parts, fmt.Sprintf("%d symlink(s): %s", len(r.Symlinks), q(r.Symlinks)))
-	}
-	if len(r.Unreadable) > 0 {
-		parts = append(parts, fmt.Sprintf("%d unreadable dir(s): %s", len(r.Unreadable), q(r.Unreadable)))
-	}
-	return strings.Join(parts, "; ")
-}
-
-// quoted joins at most maxPathsPerAlert paths, each strconv-quoted, and
-// counts the rest.
-func (Result) quoted(xs []string) string {
-	shown := xs
-	if len(shown) > maxPathsPerAlert {
-		shown = shown[:maxPathsPerAlert]
-	}
-	out := make([]string, len(shown))
-	for i, x := range shown {
-		out[i] = strconv.Quote(x)
-	}
-	s := strings.Join(out, ", ")
-	if extra := len(xs) - len(shown); extra > 0 {
-		s += fmt.Sprintf(" and %d more", extra)
-	}
-	return s
-}
-
-// Scan walks the brain dir and reports every symlink in it and every
-// directory it could not read, continuing past both. Only the ROOT .git is
-// skipped (it is brain-sync's, and no reader walks it); a nested .git is
-// scanned like any other directory. brainDir itself may be a symlink (a
-// volume mount); it is resolved first. The error is non-nil when the root
-// cannot be resolved (wrapping os.ErrNotExist when it is missing) or cannot be
-// listed.
-func Scan(brainDir string) (Result, error) {
-	root, err := filepath.EvalSymlinks(brainDir)
-	if err != nil {
-		return Result{}, fmt.Errorf("resolve brain dir: %w", err)
-	}
-	var r Result
-	rootGit := filepath.Join(root, ".git")
-	walkErr := filepath.WalkDir(root, func(p string, d fs.DirEntry, err error) error {
-		rel, _ := filepath.Rel(root, p)
-		rel = filepath.ToSlash(rel)
-		if err != nil {
-			if p == root {
-				return err
-			}
-			r.Unreadable = append(r.Unreadable, rel)
-			if d != nil && d.IsDir() {
-				return filepath.SkipDir
-			}
-			return nil
-		}
-		if d.IsDir() && p == rootGit {
-			return filepath.SkipDir
-		}
-		if d.Type()&os.ModeSymlink != 0 {
-			r.Symlinks = append(r.Symlinks, rel)
-		}
-		return nil
-	})
-	sort.Strings(r.Symlinks)
-	sort.Strings(r.Unreadable)
-	if walkErr != nil {
-		// Only the root's own error reaches here (deeper errors are recorded
-		// as Unreadable). A root that cannot be listed cannot be shown clean
-		// (PR #159 round 2: discarding this reported clean while search
-		// served a planted symlink).
-		return r, fmt.Errorf("scan brain dir: %w", walkErr)
-	}
-	return r, nil
-}
-
-// Watch rescans every interval (DefaultInterval if non-positive) until ctx
-// ends. Every symlink found is removed (the link, never its target:
-// hyperguild#157 decision), so one is readable for at most one interval.
-// Each removal is an alert; a persistent finding (a link it could not remove,
-// an unreadable dir, a scan error) alerts once per distinct state. Alerts
-// queue until Notify succeeds (see alertQueue): an outage delays them, and
-// any that do not fit the bounded queue, or are undeliverable, are counted in
-// a summary that is never dropped, so every incident is delivered or counted.
-func Watch(ctx context.Context, brainDir string, interval time.Duration, n Notifier) {
-	if interval <= 0 {
-		interval = DefaultInterval
-	}
-	t := time.NewTicker(interval)
-	defer t.Stop()
-	q := &alertQueue{}
-	reported := ""
-	for {
-		select {
-		case <-ctx.Done():
-			return
-		case <-t.C:
-		}
-		r, err := Scan(brainDir)
-		key := ""
-		if err != nil {
-			key = "cannot scan the brain dir: " + err.Error()
-		} else {
-			removed, failed := removeSymlinks(brainDir, r.Symlinks)
-			if len(removed) > 0 {
-				slog.Error("brain symlink tripwire removed symlinks", "count", len(removed))
-				q.push(fmt.Sprintf("brain symlink tripwire (hyperguild#157): removed %d symlink(s) from the brain dir: %s",
-					len(removed), Result{}.quoted(removed)))
-			}
-			key = Result{Symlinks: failed, Unreadable: r.Unreadable}.String()
-		}
-		if key != reported {
-			reported = key
-			if key != "" {
-				slog.Error("brain symlink tripwire", "finding", key)
-				q.push("brain symlink tripwire (hyperguild#157): " + key +
-					". Readers may follow symlinks out of the brain; fix them.")
-			}
-		}
-		q.flush(ctx, n)
-	}
-}
-
-// alertQueue holds alerts until Notify accepts them. It is bounded (at most
-// maxPending queued) and loses nothing from the record: every overflow and
-// every dropped message increments suppressed, sent as a summary that is
-// retried every tick and never dropped.
-//
-// A message is dropped only when the notifier rejects it permanently (an
-// error with Permanent() == true, e.g. ntfy 413). Every other failure is an
-// outage, and nothing is dropped however long it lasts (PR #160 round 2:
-// dropping after N raw failures lost the only incident of a long outage).
-// Each flush tries every queued message, so one undeliverable message cannot
-// block the others.
-type alertQueue struct {
-	items      []string
-	suppressed int
-}
-
-func (q *alertQueue) push(msg string) {
-	if len(q.items) >= maxPending {
-		q.suppressed++
-		return
-	}
-	q.items = append(q.items, msg)
-}
-
-func (q *alertQueue) flush(ctx context.Context, n Notifier) {
-	if n == nil {
-		q.items, q.suppressed = nil, 0
-		return
-	}
-	kept := q.items[:0]
-	for _, msg := range q.items {
-		err := n.Notify(ctx, msg)
-		switch {
-		case err == nil:
-		case permanent(err):
-			slog.Error("symlink tripwire alert rejected permanently; counted in the summary", "err", err)
-			q.suppressed++
-		default:
-			slog.Warn("symlink tripwire notify failed; will retry", "err", err)
-			kept = append(kept, msg)
-		}
-	}
-	q.items = kept
-	if q.suppressed > 0 {
-		msg := fmt.Sprintf("brain symlink tripwire (hyperguild#157): %d further alert(s) were suppressed or undeliverable; check the ingestion logs", q.suppressed)
-		if err := n.Notify(ctx, msg); err == nil {
-			q.suppressed = 0
-		}
-	}
-}
-
-// permanent reports whether err says the message itself can never be sent.
-func permanent(err error) bool {
-	var p interface{ Permanent() bool }
-	return errors.As(err, &p) && p.Permanent()
-}
-
-// removeSymlinks unlinks each brain-relative symlink through an os.Root on
-// the brain dir, after re-checking it is still a symlink. Removing a symlink
-// never touches its target. It returns what was removed and what was not.
-func removeSymlinks(brainDir string, rels []string) (removed, failed []string) {
-	if len(rels) == 0 {
-		return nil, nil
-	}
-	resolved, err := filepath.EvalSymlinks(brainDir)
-	if err != nil {
-		return nil, rels
-	}
-	root, err := os.OpenRoot(resolved)
-	if err != nil {
-		return nil, rels
-	}
-	defer func() { _ = root.Close() }()
-	for _, rel := range rels {
-		fi, err := root.Lstat(rel)
-		if err != nil || fi.Mode()&os.ModeSymlink == 0 {
-			failed = append(failed, rel)
-			continue
-		}
-		// root.Remove, not os.RemoveAll: if the link is swapped for a
-		// non-empty directory after the Lstat, Remove refuses rather than
-		// deleting it recursively, and it cannot act outside the root.
-		if err := root.Remove(rel); err != nil {
-			failed = append(failed, rel)
-			continue
-		}
-		removed = append(removed, rel)
-	}
-	return removed, failed
-}

ingestion/internal/symlinkguard/symlinkguard_test.go

@@ -1,498 +0,0 @@
-package symlinkguard
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"os"
-	"path/filepath"
-	"strconv"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// hyperguild#157: the brain dir is a Syncthing sendreceive folder and
-// Syncthing syncs symlinks; several readers follow them out of the brain.
-// Until every reader goes through an os.Root, a symlink anywhere in the brain,
-// or a directory the scan cannot read (which could hide one), is an incident.
-
-func TestScanReportsSymlinksAtEveryDepthIncludingNestedGit(t *testing.T) {
-	brain := t.TempDir()
-	outside := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "wiki", "w", "facts", ".git"), 0o755))
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, ".git", "objects"), 0o755))
-	require.NoError(t, os.Symlink(filepath.Join(outside, "f"), filepath.Join(brain, "wiki", "w", "facts", "leak.md")))
-	require.NoError(t, os.Symlink(outside, filepath.Join(brain, "wiki", "dirlink")))
-	// PR #159 review: only the ROOT .git is skipped; a nested .git is not
-	// special to the brain readers, which walk into it.
-	require.NoError(t, os.Symlink(filepath.Join(outside, "g"), filepath.Join(brain, "wiki", "w", "facts", ".git", "leak.md")))
-	require.NoError(t, os.Symlink(outside, filepath.Join(brain, ".git", "objects", "alt")))
-
-	r, err := Scan(brain)
-	require.NoError(t, err)
-	assert.ElementsMatch(t, []string{"wiki/w/facts/leak.md", "wiki/dirlink", "wiki/w/facts/.git/leak.md"}, r.Symlinks)
-	assert.Empty(t, r.Unreadable)
-}
-
-// PR #159 review: WalkDir stopped at the first unreadable directory and the
-// startup check passed, while search (which keeps walking) served a planted
-// symlink. Scan now records the unreadable dir and keeps going.
-func TestScanReportsUnreadableDirsAndKeepsWalkingPastThem(t *testing.T) {
-	if os.Geteuid() == 0 {
-		t.Skip("root reads mode-000 directories")
-	}
-	brain := t.TempDir()
-	locked := filepath.Join(brain, "aaa")
-	require.NoError(t, os.MkdirAll(locked, 0o755))
-	require.NoError(t, os.Chmod(locked, 0o000))
-	t.Cleanup(func() { _ = os.Chmod(locked, 0o755) })
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "zzz-planted")))
-
-	r, err := Scan(brain)
-	require.NoError(t, err)
-	assert.Equal(t, []string{"aaa"}, r.Unreadable)
-	assert.Equal(t, []string{"zzz-planted"}, r.Symlinks, "the walk continues past the unreadable dir")
-}
-
-func TestScanResolvesASymlinkedRootAndReportsSymlinkedEntriesInsideIt(t *testing.T) {
-	real := t.TempDir()
-	link := filepath.Join(t.TempDir(), "brain")
-	require.NoError(t, os.Symlink(real, link))
-	require.NoError(t, os.WriteFile(filepath.Join(real, "n.md"), []byte("x"), 0o644))
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(real, "inner")))
-	r, err := Scan(link)
-	require.NoError(t, err)
-	assert.Equal(t, []string{"inner"}, r.Symlinks)
-}
-
-func TestScanOfAMissingRootIsErrNotExist(t *testing.T) {
-	_, err := Scan(filepath.Join(t.TempDir(), "nope"))
-	assert.True(t, errors.Is(err, os.ErrNotExist), "got %v", err)
-}
-
-type recNotifier struct {
-	mu   sync.Mutex
-	msgs []string
-	fail int // fail the first N calls
-}
-
-func (r *recNotifier) Notify(_ context.Context, m string) error {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-	r.msgs = append(r.msgs, m)
-	if r.fail > 0 {
-		r.fail--
-		return errors.New("ntfy down")
-	}
-	return nil
-}
-
-func (r *recNotifier) count() int { r.mu.Lock(); defer r.mu.Unlock(); return len(r.msgs) }
-
-func TestWatchNotifiesOncePerDistinctSetAndAgainForANewSet(t *testing.T) {
-	brain := t.TempDir()
-	n := &recNotifier{}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-
-	time.Sleep(50 * time.Millisecond)
-	assert.Zero(t, n.count(), "a clean brain raises nothing")
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "first")))
-	require.Eventually(t, func() bool { return n.count() == 1 }, 2*time.Second, 10*time.Millisecond)
-	time.Sleep(60 * time.Millisecond)
-	assert.Equal(t, 1, n.count(), "the same set is reported once, not every tick")
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "second")))
-	require.Eventually(t, func() bool { return n.count() == 2 }, 2*time.Second, 10*time.Millisecond)
-}
-
-// PR #159 review: last was recorded before Notify, so an alert lost to an
-// ntfy outage was never retried while the symlink stayed.
-func TestWatchRetriesAnAlertThatFailedToSend(t *testing.T) {
-	brain := t.TempDir()
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "planted")))
-	n := &recNotifier{fail: 2}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-	require.Eventually(t, func() bool { return n.count() == 3 }, 2*time.Second, 10*time.Millisecond)
-	time.Sleep(60 * time.Millisecond)
-	assert.Equal(t, 3, n.count(), "after one successful send, no more")
-}
-
-func TestWatchAlertsOnAnUnreadableDir(t *testing.T) {
-	if os.Geteuid() == 0 {
-		t.Skip("root reads mode-000 directories")
-	}
-	brain := t.TempDir()
-	locked := filepath.Join(brain, "locked")
-	require.NoError(t, os.MkdirAll(locked, 0o755))
-	require.NoError(t, os.Chmod(locked, 0o000))
-	t.Cleanup(func() { _ = os.Chmod(locked, 0o755) })
-	n := &recNotifier{}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-	require.Eventually(t, func() bool { return n.count() == 1 }, 2*time.Second, 10*time.Millisecond)
-	assert.Contains(t, n.msgs[0], "locked")
-}
-
-// PR #159 review: a non-positive interval panicked time.NewTicker inside the
-// goroutine and crashlooped the server.
-func TestWatchToleratesANonPositiveInterval(t *testing.T) {
-	brain := t.TempDir()
-	ctx, cancel := context.WithCancel(context.Background())
-	done := make(chan struct{})
-	go func() { Watch(ctx, brain, 0, nil); close(done) }()
-	cancel()
-	select {
-	case <-done:
-	case <-time.After(2 * time.Second):
-		t.Fatal("Watch did not return on cancel")
-	}
-}
-
-// PR #159 round 2: a brain root that can be entered but not listed (mode
-// 0100) made WalkDir fail at the root; the error was discarded and Scan
-// reported clean, while search (which goes straight into wiki/) still served
-// a planted symlink. A root that cannot be listed is now an error.
-func TestScanOfAnUnlistableRootIsAnError(t *testing.T) {
-	if os.Geteuid() == 0 {
-		t.Skip("root lists mode-0100 directories")
-	}
-	brain := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "wiki"), 0o755))
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "wiki", "leak.md")))
-	require.NoError(t, os.Chmod(brain, 0o100))
-	t.Cleanup(func() { _ = os.Chmod(brain, 0o755) })
-	_, err := Scan(brain)
-	require.Error(t, err)
-	assert.False(t, errors.Is(err, os.ErrNotExist), "an unlistable root is not a missing root")
-}
-
-// The same set that disappears and comes back is reported again.
-func TestWatchReportsASetAgainAfterItWasCleared(t *testing.T) {
-	brain := t.TempDir()
-	link := filepath.Join(brain, "planted")
-	n := &recNotifier{}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-	require.NoError(t, os.Symlink(t.TempDir(), link))
-	require.Eventually(t, func() bool { return n.count() == 1 }, 2*time.Second, 10*time.Millisecond)
-	// The tripwire removed it; planting it again is a new event.
-	require.Eventually(t, func() bool { _, err := os.Lstat(link); return os.IsNotExist(err) }, 2*time.Second, 10*time.Millisecond)
-	require.NoError(t, os.Symlink(t.TempDir(), link))
-	require.Eventually(t, func() bool { return n.count() == 2 }, 2*time.Second, 10*time.Millisecond)
-}
-
-// hyperguild#157 decision: the runtime tripwire removes a symlink it finds
-// (the link, never its target), so it is readable for at most one interval
-// instead of until a human acts, and the alert says what was removed.
-func TestWatchRemovesAnOutsideFileLinkButNotItsTargetOrRegularFiles(t *testing.T) {
-	brain := t.TempDir()
-	outside := filepath.Join(t.TempDir(), "target.md")
-	require.NoError(t, os.WriteFile(outside, []byte("keep me"), 0o644))
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "wiki"), 0o755))
-	link := filepath.Join(brain, "wiki", "leak.md")
-	require.NoError(t, os.Symlink(outside, link))
-	regular := filepath.Join(brain, "wiki", "note.md")
-	require.NoError(t, os.WriteFile(regular, []byte("note"), 0o644))
-
-	n := &recNotifier{}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-
-	require.Eventually(t, func() bool {
-		_, err := os.Lstat(link)
-		return os.IsNotExist(err)
-	}, 2*time.Second, 10*time.Millisecond, "the symlink is removed")
-	require.Eventually(t, func() bool { return n.count() >= 1 }, 2*time.Second, 10*time.Millisecond)
-	b, err := os.ReadFile(outside)
-	require.NoError(t, err)
-	assert.Equal(t, "keep me", string(b), "the target is untouched")
-	b, err = os.ReadFile(regular)
-	require.NoError(t, err)
-	assert.Equal(t, "note", string(b), "regular files are untouched")
-	n.mu.Lock()
-	defer n.mu.Unlock()
-	assert.Contains(t, n.msgs[0], "removed")
-	assert.Contains(t, n.msgs[0], "wiki/leak.md")
-}
-
-func TestDefaultIntervalIsThirtySeconds(t *testing.T) {
-	assert.Equal(t, 30*time.Second, DefaultInterval)
-}
-
-// PR #160 review: the Lstat re-check and the os.Root confinement in
-// removeSymlinks had no test. Anything that is not a symlink inside the brain
-// is reported failed and nothing is deleted.
-func TestRemoveSymlinksRefusesNonSymlinksEscapesAndPathsThroughLinks(t *testing.T) {
-	brain := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "wiki", "real"), 0o755))
-	regular := filepath.Join(brain, "wiki", "note.md")
-	require.NoError(t, os.WriteFile(regular, []byte("note"), 0o644))
-	inLinked := filepath.Join(brain, "wiki", "real", "x.md")
-	require.NoError(t, os.WriteFile(inLinked, []byte("x"), 0o644))
-	require.NoError(t, os.Symlink(filepath.Join(brain, "wiki", "real"), filepath.Join(brain, "wiki", "linkdir")))
-	outside := filepath.Join(filepath.Dir(brain), "outside-157.md")
-	require.NoError(t, os.WriteFile(outside, []byte("o"), 0o644))
-	t.Cleanup(func() { _ = os.Remove(outside) })
-
-	removed, failed := removeSymlinks(brain, []string{
-		"wiki/note.md", "wiki/linkdir/x.md", "../outside-157.md", "wiki/missing.md",
-	})
-	assert.Empty(t, removed)
-	assert.ElementsMatch(t, []string{"wiki/note.md", "wiki/linkdir/x.md", "../outside-157.md", "wiki/missing.md"}, failed)
-	for _, p := range []string{regular, inLinked, outside} {
-		_, err := os.Stat(p)
-		assert.NoError(t, err, "%s must not be deleted", p)
-	}
-}
-
-// Dir targets and in-brain targets survive too, not only an outside file.
-func TestWatchRemovesDirAndInBrainLinksButNotTheirTargets(t *testing.T) {
-	brain := t.TempDir()
-	outsideDir := t.TempDir()
-	require.NoError(t, os.WriteFile(filepath.Join(outsideDir, "keep.md"), []byte("keep"), 0o644))
-	require.NoError(t, os.MkdirAll(filepath.Join(brain, "wiki"), 0o755))
-	inBrain := filepath.Join(brain, "wiki", "target.md")
-	require.NoError(t, os.WriteFile(inBrain, []byte("t"), 0o644))
-	require.NoError(t, os.Symlink(outsideDir, filepath.Join(brain, "wiki", "dirlink")))
-	require.NoError(t, os.Symlink(inBrain, filepath.Join(brain, "wiki", "inlink.md")))
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, nil)
-	require.Eventually(t, func() bool {
-		r, err := Scan(brain)
-		return err == nil && len(r.Symlinks) == 0
-	}, 2*time.Second, 10*time.Millisecond)
-	for _, p := range []string{filepath.Join(outsideDir, "keep.md"), inBrain} {
-		_, err := os.Stat(p)
-		assert.NoError(t, err, "%s must survive", p)
-	}
-}
-
-// PR #160 review: the planter chooses the paths. An alert names at most
-// maxPathsPerAlert of them and counts the rest, so its size stays bounded.
-func TestWatchAlertNamesBoundedPathsAndCountsTheRest(t *testing.T) {
-	brain := t.TempDir()
-	for i := 0; i < 50; i++ {
-		require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, strings.Repeat("n", 100)+strconv.Itoa(i))))
-	}
-	n := &recNotifier{}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-	require.Eventually(t, func() bool { return n.count() >= 1 }, 2*time.Second, 10*time.Millisecond)
-	n.mu.Lock()
-	msg := n.msgs[0]
-	n.mu.Unlock()
-	assert.Contains(t, msg, "removed 50 symlink(s)")
-	assert.Contains(t, msg, "and 40 more")
-	assert.Less(t, len(msg), 2500, "alert size is bounded regardless of how many links were planted")
-}
-
-// rejectNotifier refuses every message containing a marker, forever.
-type rejectNotifier struct {
-	recNotifier
-	reject string
-}
-
-// permanentErr is a rejection the notifier says can never succeed (like ntfy 413).
-type permanentErr struct{}
-
-func (permanentErr) Error() string   { return "413 payload too large" }
-func (permanentErr) Permanent() bool { return true }
-
-func (r *rejectNotifier) Notify(ctx context.Context, m string) error {
-	if strings.Contains(m, r.reject) {
-		r.mu.Lock()
-		r.msgs = append(r.msgs, "REJECTED")
-		r.mu.Unlock()
-		return permanentErr{}
-	}
-	return r.recNotifier.Notify(ctx, m)
-}
-
-// PR #160 review: one message the server will never accept blocked every
-// later alert forever (head-of-line). It is dropped after maxAttempts.
-func TestWatchDropsAMessageThatNeverSendsSoLaterAlertsFlow(t *testing.T) {
-	brain := t.TempDir()
-	n := &rejectNotifier{reject: "POISON"}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 10*time.Millisecond, n)
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "POISON")))
-	time.Sleep(30 * time.Millisecond)
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "later")))
-	require.Eventually(t, func() bool {
-		n.mu.Lock()
-		defer n.mu.Unlock()
-		for _, m := range n.msgs {
-			if strings.Contains(m, "later") {
-				return true
-			}
-		}
-		return false
-	}, 3*time.Second, 10*time.Millisecond, "a later alert is delivered despite a poison message")
-}
-
-// toggleNotifier fails while down is set.
-type toggleNotifier struct {
-	recNotifier
-	down atomic.Bool
-}
-
-func (r *toggleNotifier) Notify(ctx context.Context, m string) error {
-	if r.down.Load() {
-		return errors.New("ntfy down")
-	}
-	return r.recNotifier.Notify(ctx, m)
-}
-
-// PR #160 review: an outage queued one message per removal, unbounded. The
-// queue holds at most maxPending messages; the rest become one summary.
-func TestWatchQueueIsBoundedDuringAnOutage(t *testing.T) {
-	brain := t.TempDir()
-	n := &toggleNotifier{}
-	n.down.Store(true)
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 5*time.Millisecond, n)
-	for i := 0; i < 30; i++ {
-		link := filepath.Join(brain, "p"+strconv.Itoa(i))
-		require.NoError(t, os.Symlink(t.TempDir(), link))
-		require.Eventually(t, func() bool { _, err := os.Lstat(link); return os.IsNotExist(err) }, 2*time.Second, 2*time.Millisecond)
-	}
-	n.down.Store(false)
-	require.Eventually(t, func() bool { return n.count() >= 1 }, 2*time.Second, 5*time.Millisecond)
-	time.Sleep(100 * time.Millisecond)
-	assert.LessOrEqual(t, n.count(), maxPending+1, "queued alerts plus at most one suppression summary")
-	n.mu.Lock()
-	defer n.mu.Unlock()
-	found := false
-	for _, m := range n.msgs {
-		if strings.Contains(m, "suppressed") {
-			found = true
-		}
-	}
-	assert.True(t, found, "suppressed alerts are counted in a summary")
-}
-
-// Within the bound, every alert queued during an outage is delivered after
-// it, each naming its own removal (PR #160 review: truncating the queue after
-// the first send stayed green).
-func TestWatchDeliversEveryQueuedAlertAfterAShortOutage(t *testing.T) {
-	brain := t.TempDir()
-	n := &toggleNotifier{}
-	n.down.Store(true)
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 5*time.Millisecond, n)
-	for _, name := range []string{"qa", "qb", "qc"} {
-		link := filepath.Join(brain, name)
-		require.NoError(t, os.Symlink(t.TempDir(), link))
-		require.Eventually(t, func() bool { _, err := os.Lstat(link); return os.IsNotExist(err) }, 2*time.Second, 2*time.Millisecond)
-	}
-	n.down.Store(false)
-	require.Eventually(t, func() bool { return n.count() == 3 }, 2*time.Second, 5*time.Millisecond)
-	n.mu.Lock()
-	defer n.mu.Unlock()
-	for i, name := range []string{"qa", "qb", "qc"} {
-		assert.Contains(t, n.msgs[i], strconv.Quote(name))
-	}
-}
-
-// PR #160 round 2: dropping after N failures could not tell a poison message
-// from an outage, so a 15-minute outage silently lost the only incident. A
-// message is only dropped when it keeps failing while others send; through
-// an outage nothing is dropped, however long.
-func TestWatchLosesNoAlertThroughALongOutage(t *testing.T) {
-	brain := t.TempDir()
-	n := &toggleNotifier{}
-	n.down.Store(true)
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 2*time.Millisecond, n)
-	link := filepath.Join(brain, "only-incident")
-	require.NoError(t, os.Symlink(t.TempDir(), link))
-	require.Eventually(t, func() bool { _, err := os.Lstat(link); return os.IsNotExist(err) }, 2*time.Second, 2*time.Millisecond)
-	time.Sleep(200 * time.Millisecond) // ~100 ticks of outage, far past any attempt limit
-	n.down.Store(false)
-	require.Eventually(t, func() bool { return n.count() >= 1 }, 2*time.Second, 5*time.Millisecond)
-	n.mu.Lock()
-	defer n.mu.Unlock()
-	assert.Contains(t, n.msgs[0], strconv.Quote("only-incident"))
-}
-
-// Every removal is either delivered or counted in the suppression summary:
-// none disappears from the record (round 2: 74 of 300 were in neither).
-func TestWatchAccountsForEveryRemovalDuringAnOutage(t *testing.T) {
-	brain := t.TempDir()
-	n := &toggleNotifier{}
-	n.down.Store(true)
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 2*time.Millisecond, n)
-	const plants = 25
-	for i := 0; i < plants; i++ {
-		link := filepath.Join(brain, "acct"+strconv.Itoa(i))
-		require.NoError(t, os.Symlink(t.TempDir(), link))
-		require.Eventually(t, func() bool { _, err := os.Lstat(link); return os.IsNotExist(err) }, 2*time.Second, 1*time.Millisecond)
-	}
-	n.down.Store(false)
-	require.Eventually(t, func() bool {
-		n.mu.Lock()
-		defer n.mu.Unlock()
-		for _, m := range n.msgs {
-			if strings.Contains(m, "suppressed") {
-				return true
-			}
-		}
-		return false
-	}, 2*time.Second, 5*time.Millisecond)
-	time.Sleep(50 * time.Millisecond)
-	n.mu.Lock()
-	defer n.mu.Unlock()
-	delivered, counted := 0, 0
-	for _, m := range n.msgs {
-		if strings.Contains(m, "removed 1 symlink(s)") {
-			delivered++
-		}
-		if i := strings.Index(m, "): "); i >= 0 && strings.Contains(m, "suppressed") {
-			_, _ = fmt.Sscanf(m[i+3:], "%d", &counted)
-		}
-	}
-	assert.Equal(t, plants, delivered+counted, "delivered %d + counted %d must equal %d removals", delivered, counted, plants)
-}
-
-// A poison message is still dropped (others send while it fails), and the
-// drop is counted in the summary.
-func TestWatchDropsAPoisonMessageAndCountsIt(t *testing.T) {
-	brain := t.TempDir()
-	n := &rejectNotifier{reject: "POISON"}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go Watch(ctx, brain, 5*time.Millisecond, n)
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "POISON")))
-	time.Sleep(20 * time.Millisecond)
-	require.NoError(t, os.Symlink(t.TempDir(), filepath.Join(brain, "fine")))
-	require.Eventually(t, func() bool {
-		n.mu.Lock()
-		defer n.mu.Unlock()
-		for _, m := range n.msgs {
-			if strings.Contains(m, "1 further alert(s)") {
-				return true
-			}
-		}
-		return false
-	}, 3*time.Second, 5*time.Millisecond, "the dropped poison alert is counted in a summary")
-}

ingestion/internal/vectorstore/sync.go

@@ -2,15 +2,12 @@ package vectorstore
 
 import (
 	"context"
-	"errors"
 	"fmt"
-	"io/fs"
 	"log/slog"
-	"path"
+	"os"
+	"path/filepath"
 	"strings"
 	"time"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
 )
 
 // Embedder produces dense vectors. The embed package's Client satisfies
@@ -93,38 +90,31 @@ func Sync(ctx context.Context, brainDir string, store Store, embedder Embedder)
 	}
 	seenParents := make(map[string]struct{})
 
-	// Through the brain root, regular files only (hyperguild#157): the brain
-	// is a Syncthing folder, and os.ReadFile followed a synced symlink into
-	// the embeddings and blocked on a FIFO.
-	bfs, err := brainfs.Open(brainDir)
-	if err != nil {
-		return res, fmt.Errorf("open brain: %w", err)
-	}
-	defer func() { _ = bfs.Close() }()
-
 	for _, sub := range scanDirs {
-		if _, err := bfs.Lstat(sub); errors.Is(err, fs.ErrNotExist) {
+		root := filepath.Join(brainDir, sub)
+		if _, err := os.Stat(root); os.IsNotExist(err) {
 			continue
 		}
-		// Any other walk error, including a scan root that is a symlink,
+
-		// aborts the run below.
+		err = filepath.WalkDir(root, func(path string, d os.DirEntry, err error) error {
-		var walkErr error
+			if err != nil {
-		onErr := func(rel string, err error) {
+				return err
-			if walkErr == nil {
-				walkErr = fmt.Errorf("%s: %w", rel, err)
 			}
-		}
+			if d.IsDir() || !strings.HasSuffix(path, ".md") || d.Name() == "_index.md" {
-		err = bfs.WalkRegular(sub, func(relSlash string) error {
-			if !strings.HasSuffix(relSlash, ".md") || path.Base(relSlash) == "_index.md" {
 				return nil
 			}
+			rel, err := filepath.Rel(brainDir, path)
+			if err != nil {
+				return err
+			}
+			relSlash := filepath.ToSlash(rel)
 			seenParents[relSlash] = struct{}{}
 
 			if ps, ok := parents[relSlash]; ok {
 				// File already has chunks in the store. Re-embed only when
 				// the file has been edited since the oldest chunk was
 				// written. Tolerate clock skew with a sub-second grace.
-				info, statErr := bfs.Lstat(relSlash)
+				info, statErr := d.Info()
 				if statErr != nil {
 					res.Errors = append(res.Errors, fmt.Errorf("stat %s: %w", relSlash, statErr))
 					return nil
@@ -142,7 +132,7 @@ func Sync(ctx context.Context, brainDir string, store Store, embedder Embedder)
 				}
 			}
 
-			content, readErr := bfs.ReadRegular(relSlash)
+			content, readErr := os.ReadFile(path)
 			if readErr != nil {
 				res.Errors = append(res.Errors, fmt.Errorf("read %s: %w", relSlash, readErr))
 				return nil
@@ -161,12 +151,7 @@ func Sync(ctx context.Context, brainDir string, store Store, embedder Embedder)
 				res.Added++
 			}
 			return nil
-		}, onErr)
+		})
-		if err == nil {
-			err = walkErr
-		}
-		// Abort before the delete pass: an incomplete walk would leave
-		// seenParents short and delete chunks of files that still exist.
 		if err != nil {
 			return res, fmt.Errorf("walk %s: %w", sub, err)
 		}

ingestion/internal/vectorstore/sync_root_test.go

@@ -1,126 +0,0 @@
-package vectorstore_test
-
-import (
-	"context"
-	"os"
-	"path/filepath"
-	"strings"
-	"sync"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs/brainfstest"
-	"github.com/mathiasbq/hyperguild/ingestion/internal/vectorstore"
-)
-
-// recordingEmbedder keeps every text it was asked to embed.
-type recordingEmbedder struct {
-	mu    sync.Mutex
-	texts []string
-}
-
-func (e *recordingEmbedder) Embed(_ context.Context, text string) ([]float32, error) {
-	e.mu.Lock()
-	defer e.mu.Unlock()
-	e.texts = append(e.texts, text)
-	return []float32{1}, nil
-}
-
-func (e *recordingEmbedder) all() string {
-	e.mu.Lock()
-	defer e.mu.Unlock()
-	return strings.Join(e.texts, "\n")
-}
-
-// hyperguild#157 slice 3: Sync walked wiki/ and knowledge/ and read each .md
-// with os.ReadFile, so a symlinked note had its target embedded and served by
-// semantic search, and a FIFO stalled the sync.
-func TestSyncRefusesSymlinkedNotesAndSurvivesSwapRaces(t *testing.T) {
-	brain := t.TempDir()
-	writeNote(t, brain, "wiki/w/facts/ok.md", "inside note")
-	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(brain, "wiki", "w", "facts", "leak.md")))
-
-	emb := &recordingEmbedder{}
-	store := &stubStore{}
-	_, err := vectorstore.Sync(context.Background(), brain, store, emb)
-	require.NoError(t, err)
-	assert.Contains(t, emb.all(), "inside note", "positive control: the regular note is embedded")
-	assert.NotContains(t, emb.all(), brainfstest.Sentinel)
-	for p := range store.upserts {
-		assert.NotContains(t, p, "leak.md")
-	}
-
-	p := filepath.Join(brain, "knowledge", "r.md")
-	require.NoError(t, os.MkdirAll(filepath.Dir(p), 0o755))
-	sync := func() string {
-		e := &recordingEmbedder{}
-		_, _ = vectorstore.Sync(context.Background(), brain, &stubStore{}, e)
-		return e.all()
-	}
-	brainfstest.AssertNoLeak(t, p, "inside", 1500*time.Millisecond, sync)
-	brainfstest.AssertNoHang(t, p, "inside", 1500*time.Millisecond, 6*time.Second, func() { _ = sync() })
-}
-
-// Chunks embedded from a symlinked note before this fix are deleted: the
-// note is no longer seen, so the delete pass drops its rows.
-func TestSyncDeletesChunksOfASymlinkedNote(t *testing.T) {
-	brain := t.TempDir()
-	writeNote(t, brain, "wiki/w/facts/ok.md", "inside note")
-	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(brain, "wiki", "w", "facts", "leak.md")))
-	store := &stubStore{known: map[string]time.Time{
-		"wiki/w/facts/leak.md#0001": {},
-		"wiki/w/facts/ok.md#0001":   {},
-	}}
-	_, err := vectorstore.Sync(context.Background(), brain, store, &recordingEmbedder{})
-	require.NoError(t, err)
-	assert.Equal(t, []string{"wiki/w/facts/leak.md#0001"}, store.deletes)
-}
-
-// A walk error aborts Sync before the delete pass, so chunks of files the
-// walk could not see are kept.
-func TestSyncAbortsBeforeDeletingWhenASubdirIsUnreadable(t *testing.T) {
-	if os.Geteuid() == 0 {
-		t.Skip("root ignores directory permissions")
-	}
-	brain := t.TempDir()
-	writeNote(t, brain, "wiki/w/facts/ok.md", "inside note")
-	locked := filepath.Join(brain, "wiki", "w")
-	require.NoError(t, os.Chmod(locked, 0o000))
-	t.Cleanup(func() { _ = os.Chmod(locked, 0o755) })
-	store := &stubStore{known: map[string]time.Time{"wiki/w/facts/ok.md#0001": {}}}
-	_, err := vectorstore.Sync(context.Background(), brain, store, &recordingEmbedder{})
-	assert.Error(t, err)
-	assert.Empty(t, store.deletes)
-}
-
-// A scan root that is a symlink inside the brain (knowledge -> .) was
-// followed by fs.WalkDir, aliasing raw/, sessions/ and root files into the
-// index. Sync now aborts on it, before embedding or deleting anything.
-func TestSyncAbortsOnASymlinkedScanRoot(t *testing.T) {
-	brain := t.TempDir()
-	writeNote(t, brain, "wiki/w/a.md", "wiki note")
-	writeNote(t, brain, "sessions/s1.md", "session note")
-	require.NoError(t, os.Symlink(".", filepath.Join(brain, "knowledge")))
-	emb := &recordingEmbedder{}
-	store := &stubStore{known: map[string]time.Time{"wiki/w/a.md#0001": {}}}
-	_, err := vectorstore.Sync(context.Background(), brain, store, emb)
-	assert.Error(t, err)
-	assert.NotContains(t, emb.all(), "session note")
-	for p := range store.upserts {
-		assert.False(t, strings.HasPrefix(p, "knowledge/"), "upserted %s", p)
-	}
-	assert.Empty(t, store.deletes)
-}
-
-// A missing scan root is skipped; the other root still syncs.
-func TestSyncSkipsAMissingScanRoot(t *testing.T) {
-	brain := t.TempDir()
-	writeNote(t, brain, "wiki/w/a.md", "wiki note")
-	emb := &recordingEmbedder{}
-	_, err := vectorstore.Sync(context.Background(), brain, &stubStore{}, emb)
-	require.NoError(t, err)
-	assert.Contains(t, emb.all(), "wiki note")
-}

ingestion/internal/watcher/watcher.go

@@ -48,25 +48,8 @@ func Start(ctx context.Context, cfg Config) {
 func processDir(ctx context.Context, cfg Config, date string) []error {
 	rawDir := filepath.Join(cfg.BrainDir, "raw")
 
-	// Every read goes through an os.Root on raw/ (hyperguild#153): raw/ is
-	// writable via Syncthing, and a file swapped for a symlink between the walk
-	// and the read must not lead out of it. A symlinked raw/ is refused.
-	if fi, lerr := os.Lstat(rawDir); lerr != nil {
-		if os.IsNotExist(lerr) {
-			return nil
-		}
-		return []error{fmt.Errorf("stat raw dir: %w", lerr)}
-	} else if fi.Mode()&os.ModeSymlink != 0 || !fi.IsDir() {
-		return []error{fmt.Errorf("raw dir %s is not a real directory; refusing to ingest from it", rawDir)}
-	}
-	root, err := os.OpenRoot(rawDir)
-	if err != nil {
-		return []error{fmt.Errorf("open raw root: %w", err)}
-	}
-	defer func() { _ = root.Close() }()
-
 	var errs []error
-	err = filepath.WalkDir(rawDir, func(path string, d os.DirEntry, err error) error {
+	err := filepath.WalkDir(rawDir, func(path string, d os.DirEntry, err error) error {
 		if err != nil {
 			return err
 		}
@@ -103,10 +86,6 @@ func processDir(ctx context.Context, cfg Config, date string) []error {
 		if strings.HasPrefix(d.Name(), "tunnel-candidates-") {
 			return nil
 		}
-		// Only regular files are notes; a symlink's target may be anywhere.
-		if !d.Type().IsRegular() {
-			return nil
-		}
 
 		// Skip files that have already been processed or permanently failed.
 		if _, err := os.Stat(path + ".processed"); err == nil {
@@ -116,7 +95,7 @@ func processDir(ctx context.Context, cfg Config, date string) []error {
 			return nil
 		}
 
-		if err := processFile(ctx, cfg, root, rawDir, path, date); err != nil {
+		if err := processFile(ctx, cfg, path, date); err != nil {
 			errs = append(errs, fmt.Errorf("process %s: %w", filepath.Base(path), err))
 		}
 		return nil
@@ -130,15 +109,11 @@ func processDir(ctx context.Context, cfg Config, date string) []error {
 // processFile reads a file, calls pipeline.Run, copies it to processed/ or failed/,
 // and writes a marker file next to the original so the watcher skips it next poll.
 // The original file is never deleted, keeping Syncthing-connected vaults (e.g. Obsidian) intact.
-func processFile(ctx context.Context, cfg Config, root *os.Root, rawDir, path, date string) error {
+func processFile(ctx context.Context, cfg Config, path, date string) error {
 	filename := filepath.Base(path)
 	source := deriveSource(filename)
-	rel, err := filepath.Rel(rawDir, path)
-	if err != nil {
-		return fmt.Errorf("relative path: %w", err)
-	}
 
-	content, err := extract.TextIn(root, rel)
+	content, err := extract.Text(path)
 	if err != nil {
 		return fmt.Errorf("extract text: %w", err)
 	}
@@ -151,7 +126,7 @@ func processFile(ctx context.Context, cfg Config, root *os.Root, rawDir, path, d
 			return fmt.Errorf("mkdir failed dir: %w", mkErr)
 		}
 		dest := filepath.Join(failedDir, filename)
-		if cpErr := copyFromRoot(root, rel, dest); cpErr != nil {
+		if cpErr := copyFile(path, dest); cpErr != nil {
 			return fmt.Errorf("copy to failed: %w", cpErr)
 		}
 		if mkErr := os.WriteFile(path+".failed", []byte(runErr.Error()), 0o644); mkErr != nil {
@@ -179,7 +154,7 @@ func processFile(ctx context.Context, cfg Config, root *os.Root, rawDir, path, d
 		base := strings.TrimSuffix(filename, ext)
 		dest = filepath.Join(processedDir, base+"-"+time.Now().UTC().Format("150405")+ext)
 	}
-	if err := copyFromRoot(root, rel, dest); err != nil {
+	if err := copyFile(path, dest); err != nil {
 		return fmt.Errorf("copy to processed: %w", err)
 	}
 	if err := os.WriteFile(path+".processed", []byte(date), 0o644); err != nil {
@@ -190,6 +165,26 @@ func processFile(ctx context.Context, cfg Config, root *os.Root, rawDir, path, d
 	return nil
 }
 
+// copyFile copies src to dst, creating dst if it doesn't exist.
+func copyFile(src, dst string) error {
+	in, err := os.Open(src)
+	if err != nil {
+		return fmt.Errorf("open src: %w", err)
+	}
+	defer in.Close() //nolint:errcheck
+
+	out, err := os.Create(dst)
+	if err != nil {
+		return fmt.Errorf("create dst: %w", err)
+	}
+
+	if _, err := io.Copy(out, in); err != nil {
+		out.Close() //nolint:errcheck
+		return fmt.Errorf("copy: %w", err)
+	}
+	return out.Close()
+}
+
 // deriveSource turns a filename into a human-readable source name.
 // "shape-up-book.md" → "Shape Up Book"
 func deriveSource(filename string) string {
@@ -226,30 +221,3 @@ func appendWatcherLog(brainDir, filename string, runErr error, date string) erro
 	}
 	return f.Close()
 }
-
-// copyFromRoot archives a raw/ file read through the root, refusing anything
-// that is not a regular file, so a swapped-in symlink cannot copy an outside
-// file into raw/processed/ or raw/failed/ (hyperguild#153).
-func copyFromRoot(root *os.Root, rel, dst string) error {
-	fi, err := root.Lstat(rel)
-	if err != nil {
-		return err
-	}
-	if !fi.Mode().IsRegular() {
-		return fmt.Errorf("%s: not a regular file", rel)
-	}
-	in, _, err := extract.OpenRegular(root, rel)
-	if err != nil {
-		return err
-	}
-	defer func() { _ = in.Close() }()
-	out, err := os.Create(dst)
-	if err != nil {
-		return err
-	}
-	if _, err := io.Copy(out, in); err != nil {
-		_ = out.Close()
-		return err
-	}
-	return out.Close()
-}

ingestion/internal/watcher/watcher_test.go

@@ -7,10 +7,6 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"syscall"
 	"testing"
 	"time"
 
@@ -286,107 +282,3 @@ func TestProcessDir_SkipsTunnelCandidateFiles(t *testing.T) {
 	_, err = os.Stat(filepath.Join(brainDir, "raw", "processed", date, "tunnel-candidates-2026-07-19.md"))
 	assert.True(t, os.IsNotExist(err), "tunnel-candidates file should not be copied to processed/")
 }
-
-// hyperguild#153: raw/ is writable via Syncthing, and the watcher ingests
-// whatever lands there with no API call at all. WalkDir yields symlinked
-// files, and extract.Text followed them, so a symlink to any pod-readable
-// file would be extracted into the brain. The watcher now ingests only
-// regular files, read through an os.Root on raw/.
-func TestProcessDir_IngestsTheRealNoteAndSkipsTheSymlinkBesideIt(t *testing.T) {
-	brainDir := setupBrainDir(t)
-	outside := filepath.Join(t.TempDir(), "secret.md")
-	require.NoError(t, os.WriteFile(outside, []byte("SENTINEL-153-WATCHER"), 0o644))
-	// "a-" sorts before "real": a walk that stopped at the first symlink
-	// (filepath.SkipAll — one synced link halting all ingestion) would fail
-	// the call count below (PR #156 review).
-	require.NoError(t, os.Symlink(outside, filepath.Join(brainDir, "raw", "a-leak.md")))
-	require.NoError(t, os.WriteFile(filepath.Join(brainDir, "raw", "real.md"), []byte("real note"), 0o644))
-
-	var sawSentinel bool
-	calls := 0
-	cfg := Config{BrainDir: brainDir, Interval: time.Hour, Pipeline: pipeline.Config{
-		Complete: func(_ context.Context, _, user string) (string, error) {
-			calls++
-			if strings.Contains(user, "SENTINEL-153-WATCHER") {
-				sawSentinel = true
-			}
-			b, _ := json.Marshal([]pipeline.RawPage{{Title: "X", Type: "source", Subtype: "article", Content: "## S\n\nx\n"}})
-			return string(b), nil
-		},
-		Schema: "# Schema",
-	}}
-	errs := processDir(context.Background(), cfg, time.Now().UTC().Format("2006-01-02"))
-	assert.Empty(t, errs)
-	assert.False(t, sawSentinel, "the symlink target must never reach the pipeline")
-	assert.Equal(t, 1, calls, "exactly the real note is ingested; the symlink is not a note")
-}
-
-// A symlinked raw/ is refused outright: os.OpenRoot would otherwise follow
-// it and confine reads to wherever it points.
-func TestProcessDir_RefusesASymlinkedRawDir(t *testing.T) {
-	brainDir := t.TempDir()
-	elsewhere := t.TempDir()
-	require.NoError(t, os.WriteFile(filepath.Join(elsewhere, "x.md"), []byte("SENTINEL-153-RAWLINK"), 0o644))
-	require.NoError(t, os.Symlink(elsewhere, filepath.Join(brainDir, "raw")))
-	calls := 0
-	cfg := Config{BrainDir: brainDir, Interval: time.Hour, Pipeline: pipeline.Config{
-		Complete: func(context.Context, string, string) (string, error) { calls++; return "[]", nil },
-		Schema:   "# Schema",
-	}}
-	errs := processDir(context.Background(), cfg, time.Now().UTC().Format("2006-01-02"))
-	assert.NotEmpty(t, errs, "a symlinked raw/ must be reported, not silently ingested")
-	assert.Zero(t, calls)
-}
-
-// PR #156: a FIFO swapped into raw/ between the watcher's checks and its
-// read or archive copy must not hang the watcher, which runs unattended.
-func TestProcessDir_DoesNotHangUnderAFIFOSwapRace(t *testing.T) {
-	brainDir := setupBrainDir(t)
-	raw := filepath.Join(brainDir, "raw")
-	var stop atomic.Bool
-	var wg sync.WaitGroup
-	wg.Add(1)
-	// Awaited before t.TempDir's cleanup (hyperguild#162).
-	t.Cleanup(func() { stop.Store(true); wg.Wait() })
-	go func() {
-		defer wg.Done()
-		for i := 0; !stop.Load(); i++ {
-			tmp := filepath.Join(raw, ".swap")
-			_ = os.Remove(tmp)
-			if i%2 == 0 {
-				_ = os.WriteFile(tmp, []byte("x"), 0o644)
-			} else {
-				_ = syscall.Mkfifo(tmp, 0o644)
-			}
-			_ = os.Rename(tmp, filepath.Join(raw, "r.md"))
-		}
-	}()
-	cfg := Config{BrainDir: brainDir, Interval: time.Hour, Pipeline: pipeline.Config{
-		Complete: func(context.Context, string, string) (string, error) {
-			b, _ := json.Marshal([]pipeline.RawPage{{Title: "R", Type: "source", Subtype: "article", Content: "## S\n\nx\n"}})
-			return string(b), nil
-		},
-		Schema: "# Schema",
-	}}
-	var iters atomic.Int64
-	done := make(chan struct{})
-	go func() {
-		for deadline := time.Now().Add(1500 * time.Millisecond); time.Now().Before(deadline); {
-			_ = os.Remove(filepath.Join(raw, "r.md.processed"))
-			_ = os.Remove(filepath.Join(raw, "r.md.failed"))
-			_ = processDir(context.Background(), cfg, "2026-10-03")
-			iters.Add(1)
-		}
-		close(done)
-	}()
-	select {
-	case <-done:
-		stop.Store(true)
-	case <-time.After(8 * time.Second):
-		stop.Store(true)
-		if f, err := os.OpenFile(filepath.Join(raw, "r.md"), os.O_WRONLY|syscall.O_NONBLOCK, 0); err == nil {
-			_ = f.Close()
-		}
-		t.Fatalf("the watcher hung on a swapped-in FIFO after %d iterations", iters.Load())
-	}
-}