feat(web): honest, state-aware summarize status with charm spinner (ADR-025)

Clicking Summarize polled /status, which knew only "spinning" or "done". The web
ProcessVideo recorded an outcome only on success, so a 429'd or caption-less
click left transcript_status unset and the poll silently reverted to the
Summarize button — the rate limit was invisible and the click felt broken.

- ProcessVideo now records rate_limited / none / fetched (mirrors the runner); a
  rate-limited video keeps its requested flag so the background sweep retries it.
- /status is state-aware: summary card (done), working spinner (in-flight),
  a calm "waiting on rate limit, will retry" card that keeps polling so the
  summary lands on its own (no re-click), and a terminal "no captions" card.
- Charm status text (Claude-Code / Crush inspired): the spinner cycles playful
  tapir-themed gerunds via CSS only (no JS), decorative + an sr-only stable
  status line for a11y.

Pillar A (foreground fetch priority lane) is a separate follow-up.

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

internal/web/handlers.go

@@ -495,11 +495,22 @@ func (a *App) handleStatus(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if row.Summarized || !a.Processing.Has(processingKey(userID, videoID)) {
+	// Honest, state-aware status (ADR-025). Order matters: a finished summary wins;
+	// an in-flight goroutine shows the working spinner; a recorded rate-limit shows
+	// the calm "waiting, will retry" card that keeps polling; a recorded "none" is
+	// terminal; anything else falls back to the normal card.
+	switch {
+	case row.Summarized:
+		a.render(w, r, VideoCard(*row))
+	case a.Processing.Has(processingKey(userID, videoID)):
+		a.render(w, r, processingCard(*row))
+	case row.TranscriptStatus == "rate_limited":
+		a.render(w, r, waitingCard(*row))
+	case row.TranscriptStatus == "none":
+		a.render(w, r, noCaptionsCard(*row))
+	default:
 		a.render(w, r, VideoCard(*row))
-		return
 	}
-	a.render(w, r, processingCard(*row))
 }
 
 // handleSummarizeMode toggles the user's auto/manual summarization mode. The form