# HANDOFF — 2026-09-08

## Branch / Commit State

**`main` HEAD = `081e4c1`** — take-24 (PasteKey CropBounds). Working tree carries the
real fix (uncommitted): pre-parse transparency injection + diagnostics.

## Web Overlay — the ROOT CAUSE (finally named, not guessed)

WebView2's `CapturePreviewAsync` **always honors the page's own background** — the widget
page paints html/body opaque, so the captured PNG has **no alpha-0 margins, ever**.
`DefaultBackgroundColor=Transparent` only shows through pages without a background style.
All prior takes (19-24) assumed the capture had transparent margins — it never did.
`FindContentBounds` therefore had nothing to crop to, and every blend saw alpha=255 =
black box + "transparency broken" + lost resizing. One bug, three symptoms.

**Fix applied (verify by running):**
1. `WebView2Manager.InitializeAsync`: `AddScriptToExecuteOnDocumentCreatedAsync(TransparentBackgroundScript)`
   — injects html/body `background:transparent` BEFORE the page parses/scripts run (the
   OBS user.css equivalent). NavStarting/NavCompleted keep the script as post-load re-assert.
2. Restored the take-23/24 compositor crop path (stride-correct `BlitContentRaw` +
   `CropBounds` in PasteKey) — my previous take-25 gutting was wrong.
3. Diagnostics: first capture per source dumps the RAW WebView2 PNG to
   `%TEMP%\ytLive-web-<id>.png` and logs alpha stats + FindContentBounds result to
   startup.log.

## NEXT STEP (user run required once)

Run the app with the web overlay, then:
- Read `%APPDATA%\ytLlive\startup.log` — the `alpha[min=..,max=..,mean=..,zero=..%]`
  line PROVES whether the capture is transparent now (mean near 0 + high zero% + a tight
  contentBounds = fixed) or still opaque (mean ~255 → injection didn't beat the page).
- Agent can PIL-analyze `%TEMP%\ytLive-web-<id>.png` for the true alpha bbox.

## Still Open

- Chat overlay missing from recording (separate issue — not yet touched this session)
- Audio/sync: non-event (headset volume), closed

## Landmines

- testhost shares startup.log with app — filter by time when triaging
- testhost/exe lock DLLs: `taskkill /F /IM testhost.exe /IM ytLive.exe` before rebuild
- Do NOT run full-suite vstest (WASAPI hang); flow = clean build + per-class + scope-check
- Kill app before build: `/mnt/c/Windows/System32/taskkill.exe /F /IM ytLive.exe`
- The PNG dump is written ONCE per session per source (DebugPngWritten flag)