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/web/chat.go

@@ -6,6 +6,8 @@ import (
 	"net/http"
 	"strings"
 
+	"github.com/a-h/templ"
+
 	"git.d-ma.be/mathias/tapir/internal/adapters/chat"
 	"git.d-ma.be/mathias/tapir/internal/adapters/store"
 )
@@ -43,6 +45,28 @@ type chatView struct {
 	History   []chat.Turn
 	Truncated bool
 	Error     string
+	// PostURL and Subject let the same chat panel serve an UPLOADED recording
+	// (ADR-033): where the form posts, and what the transcript is called. Empty
+	// means a YouTube video (/v/{VideoID}/chat, "video"), so existing callers are
+	// unchanged.
+	PostURL templ.SafeURL
+	Subject string
+}
+
+// postURL is where the chat form posts.
+func (v chatView) postURL() templ.SafeURL {
+	if v.PostURL != "" {
+		return v.PostURL
+	}
+	return chatURL(v.VideoID)
+}
+
+// subject is what the transcript is called in the panel's wording.
+func (v chatView) subject() string {
+	if v.Subject != "" {
+		return v.Subject
+	}
+	return "video"
 }
 
 // handleChat renders the chat page for a summarized video (GET). Entry is scoped