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/audio/ffmpeg_test.go

@@ -0,0 +1,111 @@
+package audio_test
+
+import (
+	"context"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"git.d-ma.be/mathias/tapir/internal/adapters/audio"
+)
+
+func TestFFmpegToWAV_AsksForSixteenKilohertzMonoPCMAlways(t *testing.T) {
+	// Always transcode, even when the input already is 16 kHz mono: a Teams export
+	// often is, and the point is to not ASSUME (ADR-033). Records the argv.
+	rec := filepath.Join(t.TempDir(), "argv")
+	bin := stub(t, `printf '%s\n' "$@" > `+rec+`
+for a; do last="$a"; done
+printf data > "$last"`)
+
+	err := (&audio.FFmpeg{Bin: bin}).ToWAV(context.Background(), "/spool/in", filepath.Join(t.TempDir(), "out.wav"))
+
+	require.NoError(t, err)
+	raw, err := os.ReadFile(rec)
+	require.NoError(t, err)
+	argv := strings.Split(strings.TrimSpace(string(raw)), "\n")
+	joined := " " + strings.Join(argv, " ") + " "
+	for _, want := range []string{" -ac 1 ", " -ar 16000 ", " -c:a pcm_s16le ", " -vn ", " -i /spool/in "} {
+		assert.Contains(t, joined, want)
+	}
+	assert.True(t, strings.HasSuffix(strings.TrimSpace(joined), "out.wav"), "the output path is the last argument")
+}
+
+func TestFFmpegToWAV_NonzeroExitIsAnErrorCarryingStderr(t *testing.T) {
+	bin := stub(t, `echo "moov atom not found" >&2; exit 1`)
+
+	err := (&audio.FFmpeg{Bin: bin}).ToWAV(context.Background(), "/in", filepath.Join(t.TempDir(), "o.wav"))
+
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "moov atom not found")
+}
+
+func TestFFmpegToWAV_ZeroExitWithNoOutputIsAnError(t *testing.T) {
+	bin := stub(t, `exit 0`)
+
+	err := (&audio.FFmpeg{Bin: bin}).ToWAV(context.Background(), "/in", filepath.Join(t.TempDir(), "never-written.wav"))
+
+	require.Error(t, err)
+}
+
+func TestFFmpegToWAV_MissingBinaryIsAnError(t *testing.T) {
+	err := (&audio.FFmpeg{Bin: filepath.Join(t.TempDir(), "no-ffmpeg")}).ToWAV(context.Background(), "/in", "/out.wav")
+
+	require.Error(t, err)
+	assert.False(t, errors.Is(err, context.Canceled))
+}
+
+func TestFFmpegToWAV_RestrictsWhatTheFileMayMakeFFmpegOpen(t *testing.T) {
+	rec := filepath.Join(t.TempDir(), "argv")
+	bin := stub(t, `printf '%s\n' "$@" > `+rec+`
+for a; do last="$a"; done
+printf data > "$last"`)
+
+	err := (&audio.FFmpeg{Bin: bin}).ToWAV(context.Background(), "/spool/in", filepath.Join(t.TempDir(), "o.wav"))
+
+	require.NoError(t, err)
+	args := argvOf(t, rec)
+	pw, fw, in := indexOf(args, "-protocol_whitelist"), indexOf(args, "-format_whitelist"), indexOf(args, "-i")
+	require.GreaterOrEqual(t, pw, 0, "argv: %v", args)
+	require.GreaterOrEqual(t, fw, 0, "argv: %v", args)
+	assert.Equal(t, "file,pipe", args[pw+1])
+	assert.Equal(t, audio.AllowedDemuxers, args[fw+1])
+	assert.Less(t, pw, in, "input options must come BEFORE -i or ffmpeg applies them to the output")
+	assert.Less(t, fw, in)
+}
+
+func TestFFmpegToWAV_PassesAnOutputLengthCapAfterTheInputWhenAMaximumIsSet(t *testing.T) {
+	// The duration limit is a CLAIM in the file's header; a file that lies about it can
+	// convert to hours of audio (adversarial review F2: a 2 h file claiming 10 s became a
+	// 120-minute WAV). The cap is an OUTPUT option, after -i, with a minute of slack.
+	rec := filepath.Join(t.TempDir(), "argv")
+	bin := stub(t, `printf '%s\n' "$@" > `+rec+`
+for a; do last="$a"; done
+printf data > "$last"`)
+
+	err := (&audio.FFmpeg{Bin: bin, MaxSeconds: 5400}).ToWAV(context.Background(), "/spool/in", filepath.Join(t.TempDir(), "out.wav"))
+
+	require.NoError(t, err)
+	raw, err := os.ReadFile(rec)
+	require.NoError(t, err)
+	joined := " " + strings.Join(strings.Split(strings.TrimSpace(string(raw)), "\n"), " ") + " "
+	assert.Contains(t, joined, " -t 5460 ", "limit plus a minute of slack")
+	assert.Less(t, strings.Index(joined, " -i /spool/in "), strings.Index(joined, " -t 5460 "), "-t after -i is an output cap; before it, an input one")
+}
+
+func TestFFmpegToWAV_PassesNoLengthCapWhenNoMaximumIsSet(t *testing.T) {
+	rec := filepath.Join(t.TempDir(), "argv")
+	bin := stub(t, `printf '%s\n' "$@" > `+rec+`
+for a; do last="$a"; done
+printf data > "$last"`)
+
+	require.NoError(t, (&audio.FFmpeg{Bin: bin}).ToWAV(context.Background(), "/spool/in", filepath.Join(t.TempDir(), "out.wav")))
+
+	raw, err := os.ReadFile(rec)
+	require.NoError(t, err)
+	assert.NotContains(t, " "+strings.ReplaceAll(string(raw), "\n", " ")+" ", " -t ")
+}