feat: Phase A — serve static CAD Atlas viz + self-contained context

Wire the reel-style CAD workflow atlas (signal→pod) as the served page via
go:embed. Fill PROJECT.md/README with the 9-stage workflow, three governance
gates (Ed25519 admission / dispatch-allow / var-go Oath), phase map A→C,
dogfooding model, brain deep-links and external references.

Fixes two template-go-web latent bugs surfaced by dogfooding:
- templ version skew: go.mod pinned v0.2.778 vs templ@latest generator
- .gitignore pattern *.templ.go did not match generated *_templ.go

Verified: go build · vet · golangci-lint (0 issues) · go test green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

internal/web/handler_test.go

@@ -0,0 +1,43 @@
+package web
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestRootServesAtlas(t *testing.T) {
+	srv := httptest.NewServer(NewHandler())
+	defer srv.Close()
+
+	resp, err := http.Get(srv.URL + "/")
+	if err != nil {
+		t.Fatalf("GET /: %v", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("GET / status = %d, want 200", resp.StatusCode)
+	}
+	buf := make([]byte, 4096)
+	n, _ := resp.Body.Read(buf)
+	if !strings.Contains(string(buf[:n]), "CAD") {
+		t.Fatalf("GET / body missing atlas marker %q", "CAD")
+	}
+}
+
+func TestUnknownPath404(t *testing.T) {
+	srv := httptest.NewServer(NewHandler())
+	defer srv.Close()
+
+	resp, err := http.Get(srv.URL + "/nope")
+	if err != nil {
+		t.Fatalf("GET /nope: %v", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusNotFound {
+		t.Fatalf("GET /nope status = %d, want 404", resp.StatusCode)
+	}
+}