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/config/config.go

@@ -20,6 +20,9 @@ import (
 
 // Config is Tapir's fully-resolved runtime configuration.
 type Config struct {
+	// UploadConfig is the audio-upload and private-transcription settings (ADR-033).
+	UploadConfig
+
 	// UserID is the Tapir user the run operates as. Stage 0 has exactly one.
 	// It must be a UUID: it keys the UUID user_id/video_id columns (data-model).
 	UserID string
@@ -320,6 +323,10 @@ func Load() (Config, error) {
 	}
 	c.OnboardMaxVideoSeconds = onboardMax
 
+	if c.UploadConfig, err = loadUploadConfig(); err != nil {
+		return Config{}, err
+	}
+
 	return c, nil
 }