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>

DECISIONS.md

@@ -923,6 +923,41 @@ summaries.
 
 ---
 
+## ADR-025 — Honest, state-aware foreground summarization status
+
+**Status:** Accepted (2026-06-10). **Pillar B of the manual-mode UX work** (Pillar A, foreground
+fetch priority, is a separate follow-up). Builds on ADR-014 (the rate limit the UX must make
+legible).
+
+**Context.** Clicking "Summarize" spawned a background goroutine and polled `/status`, which
+returned only two states: the spinner (in-flight) or the normal card (done). But the web
+`ProcessVideo` only recorded an outcome on *success* — a 429'd or caption-less click left
+`transcript_status` unset, so the next poll silently reverted to the "Summarize" button. The
+user saw either an endless spinner or a button that did nothing useful when clicked again. The
+binding constraint (YouTube's caption rate limit) was completely invisible.
+
+**Decision.**
+1. **Record every outcome on the web path**, mirroring the runner: `ProcessVideo` stamps
+   `rate_limited` / `none` / `fetched`. A rate-limited video keeps its requested flag so the
+   background sweep retries it; `none` and `fetched` are terminal.
+2. **`/status` is state-aware**: summarized → summary card; in-flight → working spinner;
+   `rate_limited` → a calm "waiting, will retry" card that keeps polling (every 30s) so the
+   summary appears on its own when the retry lands — the user never clicks again;
+   `none` → a terminal "no captions" card with no poll and no dead-end button.
+3. **Charm status text** (Claude-Code / Crush inspired): the working spinner cycles playful,
+   tapir-themed gerunds ("Chewing the cud…", "Munching leaves…", "Distilling the gist…") via
+   CSS only — no JS, keeping the HTMX/no-JS ethos. Decorative (aria-hidden) with a stable
+   `role=status` line for assistive tech.
+
+**Principle.** When the system cannot be fast (throttled IP), it is at least honest, and it
+self-resolves without making the user retry. Honesty is the load-bearing half — Pillar A's
+priority lane only improves the odds of a fast slot; it cannot beat an already-hot IP.
+
+**Reversibility.** Pure transport-layer + view change over the unchanged engine/ports. No
+schema change (reuses `transcript_status` from migration 007).
+
+---
+
 ## Rejected alternatives
 
 Approaches considered during the 2026-06-02 planning + grill session and **deliberately not