feat: upload audio, get a private Swedish transcript, discuss it (#33, ADR-033) (#39)

Upload a recording (audio, or video with the camera off), get a private Swedish transcript, and chat about it.

- ADR-033: RLS-scoped private transcript store; ffprobe/ffmpeg intake; gateway transcription (iguana kb-whisper, berget fallback); in-process single-replica worker; chat over the transcript (local models only).
- ADR-034: optional two-engine mode (pianissimo + kb-whisper) reconciled by a LOCAL model; off unless TAPIR_RECONCILE_BASE_MODEL is set.
- ADR-035: real progress (phases, running/quiet/lost), phase logging, every judged spot stored, merged segments.
- Hardening from four adversarial reviews: errors logged and stored as kinds never text; per-engine deadlines; converted-length check; bounded queue; client hang-ups are not errors; strict local-alias check.
- Dockerfile: static ffmpeg/ffprobe 7.0.2 pinned by sha256 (#34). Built and inspected by hand; CI does not build the image on a PR, so its first CI build is this merge.

Uploads stay OFF until TAPIR_UPLOADS_ENABLED is set in the deployment.

Closes #33, #34, #42, #43, #44.

Co-authored-by: Mathias <mthbqv@gmail.com>

internal/adapters/llm/client.go

@@ -25,12 +25,16 @@ import (
 // docs/homelab-integration.md.
 const defaultMaxTokens = 8192
 
+// defaultTemperature is what every caller got before WithTemperature existed.
+const defaultTemperature = 0.2
+
 // Client calls an OpenAI-compatible chat completions endpoint.
 type Client struct {
 	baseURL    string
 	apiKey     string
 	model      string
 	maxTokens  int
+	temp       float64
 	httpClient *http.Client
 	usageHook  func(model string, prompt, completion int)
 }
@@ -51,6 +55,35 @@ func WithMaxTokens(n int) Option {
 	}
 }
 
+// maxErrorBody bounds how much of a failing response ends up in an error message.
+const maxErrorBody = 512
+
+// HTTPError is a non-200 answer from the gateway. Its text keeps the form callers that
+// log it already rely on, with the body bounded; its Code is what code may branch on and
+// what errkind turns into a kind. The body is provider text and can echo the prompt, so
+// nothing private may persist or display Error() (ADR-035 review F3).
+type HTTPError struct {
+	Code int
+	Body string
+}
+
+func (e *HTTPError) Error() string {
+	body := e.Body
+	if len(body) > maxErrorBody {
+		body = body[:maxErrorBody] + "…"
+	}
+	return fmt.Sprintf("LLM returned %d: %s", e.Code, body)
+}
+
+// HTTPStatus implements errkind.HTTPStatuser.
+func (e *HTTPError) HTTPStatus() int { return e.Code }
+
+// WithTemperature overrides the sampling temperature. Zero IS a valid value and is sent
+// as zero: the reconciler's accuracy was measured at temperature 0 and must run there.
+func WithTemperature(t float64) Option {
+	return func(c *Client) { c.temp = t }
+}
+
 // WithUsageHook registers a callback fired after a successful completion with the
 // model and the prompt/completion token counts from the response usage block. It
 // keeps this copied, stdlib-only package (ADR-004) decoupled from metrics: the
@@ -66,6 +99,7 @@ func New(baseURL, apiKey, model string, timeout time.Duration, opts ...Option) *
 		apiKey:     apiKey,
 		model:      model,
 		maxTokens:  defaultMaxTokens,
+		temp:       defaultTemperature,
 		httpClient: &http.Client{Timeout: timeout},
 	}
 	for _, opt := range opts {
@@ -105,7 +139,7 @@ func (c *Client) Complete(ctx context.Context, system, user string) (string, err
 			{Role: "system", Content: system},
 			{Role: "user", Content: user},
 		},
-		Temperature: 0.2,
+		Temperature: c.temp,
 		MaxTokens:   c.maxTokens,
 	}
 	b, err := json.Marshal(body)
@@ -155,7 +189,7 @@ func (c *Client) Complete(ctx context.Context, system, user string) (string, err
 		return "", fmt.Errorf("read response: %w", err)
 	}
 	if resp.StatusCode != http.StatusOK {
-		return "", fmt.Errorf("LLM returned %d: %s", resp.StatusCode, out)
+		return "", &HTTPError{Code: resp.StatusCode, Body: string(out)}
 	}
 
 	var cr chatResponse

internal/adapters/llm/status_error_test.go

@@ -0,0 +1,63 @@
+package llm
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"git.d-ma.be/mathias/tapir/internal/errkind"
+)
+
+// A non-200 from the gateway is an HTTP status error: its kind can be logged and stored
+// without its body, which can echo the prompt (adversarial review F3).
+
+func failingGateway(t *testing.T, status int, body string) *httptest.Server {
+	t.Helper()
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(status)
+		_, _ = w.Write([]byte(body))
+	}))
+	t.Cleanup(srv.Close)
+	return srv
+}
+
+func TestClient_ANon200IsAnHTTPStatusErrorWhoseKindCarriesNoBody(t *testing.T) {
+	srv := failingGateway(t, http.StatusBadRequest, `{"error":"prompt was: Anders ansvarar för virket"}`)
+
+	_, err := New(srv.URL, "", "m", 5*time.Second).Complete(context.Background(), "s", "u")
+
+	if err == nil {
+		t.Fatal("expected an error")
+	}
+	if got := errkind.Of(err); got != "http_400" {
+		t.Errorf("errkind.Of = %q, want http_400", got)
+	}
+	var he *HTTPError
+	if !errors.As(err, &he) || he.Code != http.StatusBadRequest {
+		t.Errorf("error is not an *HTTPError with the status code: %v", err)
+	}
+}
+
+func TestClient_TheErrorTextIsUnchangedForCallersThatLogIt(t *testing.T) {
+	srv := failingGateway(t, http.StatusBadGateway, "upstream down")
+
+	_, err := New(srv.URL, "", "m", 5*time.Second).Complete(context.Background(), "s", "u")
+
+	if err == nil || err.Error() != "LLM returned 502: upstream down" {
+		t.Errorf("error text = %v: callers that log it already rely on this form", err)
+	}
+}
+
+func TestClient_AnEnormousErrorBodyIsBoundedInTheErrorText(t *testing.T) {
+	srv := failingGateway(t, http.StatusInternalServerError, strings.Repeat("x", 100_000))
+
+	_, err := New(srv.URL, "", "m", 5*time.Second).Complete(context.Background(), "s", "u")
+
+	if err == nil || len(err.Error()) > 1024 {
+		t.Errorf("error text is %d bytes: a gateway's whole body must not become an error message", len(err.Error()))
+	}
+}

internal/adapters/llm/temperature_test.go

@@ -0,0 +1,57 @@
+package llm
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+)
+
+// capturedTemperature runs one Complete against a fake gateway and returns the
+// "temperature" field the request carried, and whether it was present at all.
+func capturedTemperature(t *testing.T, opts ...Option) (float64, bool) {
+	t.Helper()
+	var body map[string]any
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		raw, _ := io.ReadAll(r.Body)
+		_ = json.Unmarshal(raw, &body)
+		w.Header().Set("Content-Type", "application/json")
+		_ = json.NewEncoder(w).Encode(map[string]any{"choices": []map[string]any{{"message": map[string]any{"role": "assistant", "content": "ok"}}}})
+	}))
+	defer srv.Close()
+
+	if _, err := New(srv.URL, "", "m", 5*time.Second, opts...).Complete(context.Background(), "s", "u"); err != nil {
+		t.Fatalf("Complete: %v", err)
+	}
+	v, ok := body["temperature"].(float64)
+	return v, ok
+}
+
+func TestClient_DefaultTemperatureIsUnchanged(t *testing.T) {
+	got, ok := capturedTemperature(t)
+
+	if !ok || got != 0.2 {
+		t.Fatalf("default temperature = %v (present %v), want 0.2: existing callers must not change behaviour", got, ok)
+	}
+}
+
+func TestClient_WithTemperatureZeroSendsExactlyZero(t *testing.T) {
+	// The reconciler's accuracy (92%/97%) was measured at temperature 0. Zero must be
+	// SENT, not treated as "unset" and replaced by the default.
+	got, ok := capturedTemperature(t, WithTemperature(0))
+
+	if !ok || got != 0 {
+		t.Fatalf("temperature = %v (present %v), want an explicit 0", got, ok)
+	}
+}
+
+func TestClient_WithTemperatureSendsTheGivenValue(t *testing.T) {
+	got, ok := capturedTemperature(t, WithTemperature(0.7))
+
+	if !ok || got != 0.7 {
+		t.Fatalf("temperature = %v (present %v), want 0.7", got, ok)
+	}
+}