LlamaCasty/HANDOFF.md

# HANDOFF — 2026-10-10 (desktop-"lock" fix local, uncommitted)

## At a glance
- **Branch** main (no feature branch). Pushed through `5685c5d`; everything after is local, **not
  pushed** (push at the creator's call).
- Three work units in the working tree: (1) the desktop-lock fix below, (2) the TASK 51 webcam unit,
  (3) the creator's pinned-chat unit. Do NOT mix them in one commit.

## Branch
- main (no feature branch). Pushed through `5685c5d` (TRAX toggle); everything after is local,
  **not pushed** (push at the creator's call).

## New work unit (this handoff) — READY TO VERIFY, do not commit yet
- **Fix** for the "desktop is locked once the app starts" report — `MainWindow.xaml.cs` +
  `ViewModels/MainViewModel.Background.cs` (`ShowActivated = !FullscreenGameRunningNow`, see
  `bugs.md` entry 2026-10-10). Scope-locked files: `MainWindow.xaml.cs`,
  `ViewModels/MainViewModel.Background.cs`, `ViewModels/MainViewModel.cs` (detector seam line),
  `ytLive.Tests/DesktopLockTests.cs` (new), `bugs.md`, this file.
- **Regression tests:** `DesktopLockTests` (3 tests) drive the rule through the NEW
  `FullScreenDetectorOverride` test seam (the same seam pattern as `WindowEnumeratorOverride`) —
  no real Win32 foreground state is touched: full-screen game at launch ⇒ `ShowActivated=false`;
  normal launch ⇒ still `true`; `FullscreenGameRunningNow` reflects the detector. Full suite
  **422 passed / 0 failed / 0 warnings**. Real-app reproduction still deferred to the creator.
- **To commit later (this unit only):** the two code files + the two memory files listed above.
- Verify with the creator first: launch while an exclusive-fullscreen game is the foreground — the
  game must stay live and the app must open behind/alongside it without focus steal.

## Dirty files — split by ownership
- **This work unit (COMMIT these):** `Services/BackgroundEffects/MaskSmoother.cs` (new), the smoother
  wiring in `Services/CameraManager.cs`, `ytLive.Tests/CameraManagerTests.cs` (new integration test),
  and the same-commit memory updates (`Services/index.md`, `ai.md`, `TASKS/task-51-webcam-bg-effects.md`,
  `TASKS.md` row 51, and this file) — all ship in the SAME commit.
- **NOT mine — do NOT commit:** the in-flight "pinned chat" work unit (`Models/YouTube.cs`,
  `ViewModels/MainViewModel.Chat.cs`, untracked `Helpers/RelayCommandGeneric.cs`, and **its hunks in
  `Controls/LeftPanel.xaml`** — only the webcam-properties region is TASK 51; the pinned-chat hunks
  stayed unstaged/untouched), plus the creator's untracked `Assets/llamacasty*` art.
- ⚠️ Pre-commit: `scripts/verify.sh` runs `scripts/scope-check.sh` against ALL working-tree changes —
  the not-mine files WILL flag. Pass them to the script as declared-known (checksums unchanged since
  `5685c5d`) or let the script's output be reconciled before committing.

## What just happened — two commits
1. **Jitter fix (`3057069`) — `MaskSmoother`**: per-session blend 0.75×new + 0.25×previous at the
   ONE worker (`CameraManager.RunEffectWorker` → `session.Smoother.Smooth(TrySegment(source))`).
   State on `CameraSession`, NOT the segmenter (shared app-wide, contract-pinned to raw output). Null
   resets history; first frame passes through; never aliases caller's array; ping-pong buffers (no
   per-frame LOH alloc). Weights: OBS obs-backgroundremoval 0.85 default, Jitsi 0.7/0.3 best
   (0.5/0.5 smears). Test `Temporal_Smoothing_Damps_Segmentation_Jitter_Across_Frames`: x=6 → first
   255 / smoothed 58 / raw-unsmoothed 0. ⚠️ Gotcha: worker guards a re-queued identical frame
   reference — pump frame2 as a NEW instance.
2. **Blur "heavy" fix (this commit) — quadratic radius**: `BlurRadius(strength)` = 1 + 5·s²,
   `MaxBlurRadius` 12→6 small px (≈ 24 full px max). Default 0.5 = 2 small px (was 6 under the old
   linear curve) — ~3× lighter spread. Rationale: StreamFX defaults Box blur Size to 5, author stops
   downscaled blurs ~8px. Test `Blur_default_strength_is_gentle_and_full_strength_is_strong` pins the
   mapping and step-edge behaviour (reach 9px default vs 26px max). Point-source probes vanish below
   the 0.5 rounding (3 box passes dilute a spike) — use a step edge, not a spike, to measure blur.

## Next step
- Creator verifies the desktop-lock fix: while THE DIVISION 2 (or any exclusive-fullscreen game) is the
  foreground window, launch the app — the game must stay live and the app must not yank focus. Also
  confirm a normal launch is unchanged. Then I can commit the unit and run the full suite when the
  mouse is free.

## Tests
- Full suite **422 passed / 0 failed / 0 skipped / 0 warnings** (2026-10-10; includes the 3 new
  `DesktopLockTests`). Known env flakes remain `Mix_HonorsProviderGains…` (fails while system audio
  plays) and `RealMouseDrag…` (needs an idle desktop).

## Also still open
- **Vertical-format regression (STALE, not fixed):** 1080p60 vertical selection no longer shrinks the
  capture border in the preview. Mechanism mapped (see prior summary): the crop Rectangle
  `Controls/PreviewPane.xaml:319-322` bound to `OutputRectX/Y/W/H` + `IsOutputCropped`, driven by
  `MainViewModel.Streaming.cs` `ApplyStreamQuality` from `SelectedQuality` (binding + ctor only,
  `new("Vertical 1080p60", 60, 8.0, 1080, 1920)`), `DimRects` in `MainViewModel.cs:91-94`. Root cause
  unknown — paused.
- **Vertical recording file closed:** the recording itself is 1080×1920 60fps correctly; the
  "whitespace" was the app's preview UI, not the file. Audio loudness (`ebur128`) for the private video
  was never run and the thread is closed unless the user reopens it.
- Blur-heaviness = fixed (above). Yellow-border regression = stale thread.
- ⛔ Sudo password rotation pending (user; then update both password lines in `CREDENTIALS.md`).
- TASK 56 secret scan before `gramps/LlamaCasty` goes public. TASK 55 disk hygiene queued.

## Tests
- Full suite **416 passed / 1 known env flake** at `5685c5d`; the new smoothing test passes
  standalone (1 test run, Duration < 1 s after warm). 0 build warnings. Known environment flakes:
  `Mix_HonorsProviderGains…` (fails while system audio plays), `RealMouseDrag…` (needs an idle desktop).