feat(ui): left-panel alert stack — licence indicator pinned on top, events LIFO below

Creator design (2026-11-05). A stack of red rows at the top of the left panel, above both mode grids
so it shows while editing and while live, pushing the panel's content down.

- Row 1 is the **Steam licence indicator** and nothing displaces it. It reads as status, not a
  warning: "Entitlement 30 fps · Maximum 60 fps", both numbers derived from QualityOptions and
  HasProOutput. While higher tiers are unavailable it shows a **pin** (standing indicator, no close
  control); once ownership is verified the pin becomes a **close control** and the dismissal is
  persisted (`Steam.LicenceIndicatorDismissed`), permanent while ownership holds. Losing ownership
  restores it as pinned — a change of state, not a preference. Click → About.
- **Event rows stack beneath, newest first**, one row per episode (an episode advancing its state
  updates its own row rather than adding another). Each is dismissible. Click → the Logs tab opens
  with that event's sequence range painted red (`HighlightedLogFrom/To` + `LogInRangeConverter`; two
  numbers rather than a collection because the log list is virtualised and realised rows do not
  re-evaluate on membership changes).
- Replaces the old red panel under the quality picker, which is removed.
- The Steam diagnostic text loses "Contact the creator or support" for a neutral
  "Steam licensing is not configured in this build."

Tests: `AttentionAlertStackTests` — pinned first with the status text; owned → closable and the close
survives a reload but ownership loss restores it pinned; pinned cannot be dismissed; event rows LIFO
with in-place episode updates; clicking an event opens Logs and sets its range. AboutHub + Entitlement
tests updated for the removed panel and the new wording. FAST gate: 532 passed, 0 failed, 0 warnings.

HANDOFF.md

@@ -1,40 +1,30 @@
-# HANDOFF — 2026-11-05 (TASK 64 — green/blue screen for clips)
+# HANDOFF — 2026-11-05 (alert stack + media/chroma fixes)
 
 ## State
 
-- `main`. TASK 21 complete (video file layer + its soundtrack). TASK 64 shipped through slice E:
-  a clip with a green or blue backdrop is **offered** a key on add ("Looks like a green screen —
-  Remove it"), accepting it keys the background **inside the decode pipe** (bundled ffmpeg
-  `colorkey`/`despill`), with Amount/Softness/Fringe in the panel and the settings persisted.
-  Sessions are keyed by **path + look**, so identical looks share one decoder.
-- Detection stays silent on lawns/pitches (confidence = coverage × hue tightness) and ignores
-  letterbox bars. It never acts on its own.
-- Slice F shipped too: **App Settings → Video clips → "Auto Green/Blue Screen"** (off by default,
-  high confidence only, and the panel states when a key was automatic) and **alert clips** key through
-  the same settings block (one alert box per layout).
-- Tests: `ChromaKeyDetectorTests` + `ChromaKeyApplyTests` (pipe asks ffmpeg to key; offer → accept →
-  keyed session feeds the resolver; survives save; auto-apply; alert clip keyed). App build 0 warnings.
-- **TASK 49 retired (creator ruling):** YouTube owns chat moderation — blocked words and hold-for-review
-  run before the API. What we owed it was not a wordlist but not painting what YouTube removed: the chat
-  parser now skips `tombstone` (a deleted message's text is never sent) and `hasDisplayContent:false`.
-  Same commit fixed a live bug: Super Chat read `displayString` instead of `amountDisplayString`, so every
-  amount fell back to a recomposed string.
+- `main`. TASK 21 (video layer + soundtrack), TASK 64 (green/blue screen) and TASK 32·4 (fragmented MP4)
+  are complete; TASK 49 is retired (YouTube owns chat moderation — we just don't paint tombstones).
+- **Left panel alert stack** shipped: Steam licence indicator pinned at row 1 (`Entitlement 30 fps ·
+  Maximum 60 fps`, pin → close once owned, permanent while owned), event rows LIFO beneath, click →
+  About or the Logs tab with that event's lines painted. Detail: `docs/ai/ui-surface.md`.
+- Video layer fixes this session: the preview-pane trigger whitelist (a video layer was invisible), a
+  quadratic frame copy that capped 1080p playback at 2 fps, and deadline pacing for video *and* audio.
+- Tests: 575 green, 1m50s; `FAST=1 ./scripts/verify.sh` = 527 in ~62s.
 
 ## Next action
 
-- TASK 64 is complete. Next queued: TASK 49 (chat profanity filter). Day 3's TASK 32/33 resilience slices remain outstanding —
-  32·4 (fragmented MP4) is the smallest.
+- **TASK 32·1 (blip retry)** — it pushes its episodes into the alert stack. Then 32·5 (ingest pre-flight),
+  then 32·2/32·3 (countdown + Back on air) which need YOUR measurement take: pull the network on a
+  private stream and time how long YouTube holds the broadcast.
+- Open loop: `32·4` is proven by construction only — kill ffmpeg mid-recording and play the file.
 - Do not push absent a checkpoint request.
 
 ## Landmines
 
-- **The preview pane draws frame-source layers from a whitelist of DataTriggers.** A layer type with
-  no trigger is invisible in the preview while its decode looks healthy (alert box 2026-09-26, the
-  scoreboard, and the video layer 2026-11-05). Add the trigger with the layer type; pin it with a
-  test that asserts the bound Image is Visible (`MediaPreviewDisplayTests`).
-- The old physical mouse-drag test is **deleted**; the drag arithmetic it covered is now pure and
-  tested in `DragReorderMathTests`. Nothing in the suite drives the real cursor any more.
+- **The preview pane draws frame-source layers from a whitelist of DataTriggers.** A layer type with no
+  trigger is invisible in the preview while its decode looks healthy (alert box 2026-09-26, scoreboard,
+  video layer 2026-11-05). Add the trigger with the layer type; pin it with `MediaPreviewDisplayTests`.
+- Nothing in the suite drives the real cursor any more; the drag arithmetic is pure (`DragReorderMathTests`).
 - Integration tests constructing `MainWindow` must set a temporary `LayoutPathOverride` and clear it in `finally`.
-- Media sessions are keyed by **path + look** (`MainViewModel.MediaSessionKey`); never acquire by raw
-  path, and release through `ReleaseMediaIfUnused`.
+- Media sessions are keyed by **path + look** (`MainViewModel.MediaSessionKey`); never acquire by raw path.
 - Bundled FFmpeg stays outside the single-file exe (`ExcludeFromSingleFile="true"`).