LlamaCasty/HANDOFF.md

HANDOFF — 2026-09-26 (TASK 47 shipping crash + the "nothing in the box" void both fixed; 3 local commits, NOT pushed)

Branch / Commit State

main — three local commits ahead of origin/main (= ecb329e), NOT pushed (awaiting the creator's go / milestone signal):

1. a11b15e — TASK 47 alert box video (built-in/custom clip + read-time fade + message ticker + unity audio) + AlertLayerVideoTests (fake decoder, 0 warnings, 319/319 green).
2. 7b940b6 — crash fix: AlertOverlayLayer marshals the chat-poller seam to the UI thread (regression test red pre-fix / green post-fix, both verified). Full suite 320/320.
3. (uncommitted next — this session) — silent-decoder fallback + diagnostics (see below), scope: Services/AlertOverlayLayer.cs, Services/AlertClipDecoder.cs, ytLive.Tests/AlertLayerVideoTests.cs + docs (task-47 addendum, MyMistakes.md lesson, this file). New Good Dog test green; build 0 warnings; full suite 321 with the known env flake (RealMouseDrag reorder failing while windows are up — passes with the desktop clean; unrelated to this change). scope-check.sh pending, then commit.

✅ Crash fixed (7b940b6)

The creator's first live session: test-tab alerts DID fire (11:21 startup.log: alert-clip audio in the mix, peakMix 0.375 → 0.891 with mic+loop at 0.000) but the app crashed at 11:22:01.301 on the first REAL polled message: Must create DependencySource on same Thread as the DependencyObject in DataBindEngine.ProcessCrossThreadRequests. AlertOverlayLayer.OnMessageReceived had no UI-thread marshal (ChatOverlayLayer has one); it ran RefreshAlertPreviews → UpdatePreview on the MTA poller thread and stamped alertBox.VideoImageSource (INPC + WPF-bound) with a WriteableBitmap created there. Fix + Good Dog regression test OnMessageReceived_FromPollerThread_MarshalsPreviewWritesToTheUiThread (red/green verified). MyMistakes.md: every INPC-raising seam fed by the poller must marshal WPF-object writes.

⚠️ The "nothing in the alert box" void — diagnosed + fixed (this unit)

After the crash fix the creator reported: On-Air → test → remove and re-add the Stream Alerts layer → TEST event → procs in the chat windows but nothing in the alert box. startup.log 11:44: peakMix 0.105 (no alert audio) vs 11:21's 0.375–0.891. No exception anywhere — every stage of the clip path was silent by design (UpdatePreview catch = Debug.WriteLine-only; RunAsync bare catch { } firing Completed regardless). Established the guaranteed-invisible fail: a decoder whose Start() succeeds but yields no frames AND no audio leaves _clip != null with _latestClipFrame == null → RenderClipFrame returns null forever → box transparent FOREVER; the six-animation fallback only ran on setup-time throws. (Hunted & ruled out meanwhile: LiveScene is never assigned — the encoder always renders StagedScene (MainViewModel.cs:323), so the re-added box IS in the render graph; the bake invalidates per element on add; DB row c85b46ac-… X=602 Y=26 680×200 healthy; pinned ffmpeg decodes the default clip to scale=680:200 rawvideo correctly to a file. Frame pacing silently off too: no probe → frameDuration=0.)

Fix (uncommitted): AlertOverlayLayer.Advance — a started clip that produced neither a frame nor an audio chunk inside NoFrameFallbackSeconds (1.0 s) is torn down, _elapsed resets, and the SAME alert continues as the six-animation render (never blank, never drained early). Diagnostics: BeginClip logs box id / resolved path / size + setup failure; AlertClipDecoder.RunAsync logs frame/chunk end-state + the swallowed exception. Good Dog test SilentDecoder_FallsBackToTheAnimationAfterTheNoFrameGrace: transparent inside the grace → decoder disposed past it → animation renders → drains to idle. MyMistakes.md: an alert that plays is a promise — degrade on dead-air, and a catch hiding WHY output vanished is a lie.

Follow-ups queued (NOT done in this unit)

• TASK 3 item 20 persistence half — canonical RewardEvents SQLite table + superChatEvents.list (30-day) backfill + session-report rollup (still in-memory only).
• TASK 3 item 16 (Text source); TASK 40 units A/C/D; TASK 32–36; TASK 12 master limiter — queued.
• If the alert box is STILL blank after this fix + relaunch: the new logs make the failure conclusive (look for Alert clip start: → Alert clip decode failed → Alert clip end:). The creator's Live scene also has a WebSource "Web Resource-0" bottom-right — confirm which element they watch when describing the "stream-alerts layer".
• The known pump stall (render=full-render … totalMs=147, ~6fps worst) is recorded as a pre-existing perf item, NOT part of this unit.

Around the task (carried facts)

• RealMouseDrag tests no-op while a game/fullscreen window steals the mouse — close fullscreen windows before full-suite runs; passes in isolation.
• Test-env trap: saved OAuth session loads synchronously → force vm.IsConnected in signed-in tests.
• subscriberCount YPP slice 2 needs re-consent — do not merge with other units. MARCOM.md/ MONETIZATION.md gitignored — never commit.
• API facts (TASK 44 + 45): liveChatId unavailable until broadcast live; 400 MISSING_REQUIRED_FIELD from liveChat/messages.insert = wrong body shape (missing snippet.type).
• TASK 47 sticky facts: bgra from ffmpeg is opaque (alpha=255); audio pipe = carry-buffer loop; default clip = %TEMP%\ytLive-alert-{id}.mp4; decoder per-play; DB stays user_version 10.
• ChatOverlayLayer.OnMessageReceived marshals the poller seam; AlertOverlayLayer mirrors it; the no-frame fallback lives in Advance (has the 1 s grace + diagnostics).
• Every committed change needs a close + relaunch of the running app to be seen.

Next step

1. Commit this unit with the declared scope ./scripts/scope-check.sh "Services/AlertOverlayLayer.cs" "Services/AlertClipDecoder.cs" "ytLive.Tests/AlertLayerVideoTests.cs".
2. Push the three local commits at the creator's go / milestone signal.
3. Creator to relaunch and re-run the repro (compare the 11:21 vs 11:44 behavior) — the new logs will say exactly what the decoder did.

Critical working rules (unchanged, still binding)

• Good Dog = ONE integration test per change. Scope lock + ./scripts/scope-check.sh before commit.
• Windows dotnet host for all WSL builds (/mnt/c/Program Files/dotnet/dotnet.exe, quoted paths).
• 0 warnings on real clean builds. One commit = fix + its memory (task doc, MyMistakes, handoff).
• No menus/polls with the creator; decisions asked once then held; do the work, then report.