Unit 2 of slimming the mandatory read. Verbatim move again - the four capture
blocks leave ai.md unchanged in content, and one stub carries the law.
- docs/ai/capture.md: 'Screen backdrop capture', 'Webcam capture', 'Webcam
background effects' and 'Vertical (9:16) tier camera placement', byte-
identical, grouped under backdrop / webcam / vertical headings, with a
'Related in ai.md' footer.
- ai.md stub keeps: the locked-Background model and NormalizeBackgrounds;
ActiveBackgroundImage is fed by static art only (2026-08-23 regression);
window:/picker: keys are session-scoped and a live pin beats auto-detect;
the settled WinRT interop paths (TryGetDataUnsafe, from-DXGIDevice); the
VideoFrame seam, own-catch subtype ladder and no fallback camera; one app-
level webcam identity with live-lock attainability; CameraManager as the one
effects processing point with per-session mask smoothing; geometry-only
vertical tier and the model-level rect lock.
- docs/ai/index.md gains the capture.md row; Services/index.md (2) and
TASKS/task-38-window-backdrop.md repointed.
ai.md 1,975 -> 1,558 lines. No source touched; no push.
ai.md is the mandatory read every session; at 2,702 lines / ~64k tokens it
costs the whole subsystem history even when the task never touches it. This
is a verbatim move, not a compression - nothing is deleted and each stub is
written from the moved text.
- docs/ai/frame-pipeline.md: 'Frame cadence', 'Per-element composite timing +
scene dump', 'What the first instrumented take said', 'Render budget',
'Scene compositor' and 'Live frame pipeline', byte-identical, plus a short
'Related in ai.md' footer and two stale 'below' pointers corrected.
- ai.md keeps two stubs carrying the invariants that must not be missed
(overlay on every render path, VideoFrame.Epoch, StripPool threads,
Release-only render numbers; arrival-stamped rawvideo, non-blocking submit,
stop order, burned _outputIndex judge) and links the new file.
- docs/ai/index.md + docs/index.md route the split; schema.md inventory lists
the new tier.
- 4 index-row references and 2 TASKS.md anchors repointed; ai.md's Services
row too.
Measured: ai.md 63.6k -> 47.1k tokens, 2,702 -> 1,975 lines. Progressive
disclosure per schema.md convention 5. No source touched; no push.
Encoder dual-output: StreamEnabled/RecordEnabled/RecordPath options; per-output
ffmpeg block (stream ->flv, record ->mp4); throw unless at least one output.
RecordingFile: auto-name ty-<yyyymmdd>-<start hhmm>-0000.mp4, rename-on-stop to
ty-...-<len hhmmss>.mp4 with numeric-suffix on collision. LayoutStore persists
record folder. MainViewModel: REC/ON-AIR pills, status light, single Start<->End
button (replaces Start/Stop variants), StopStream no longer signs out, explicit
session timer. About overlay widened. Sign In label + spacing before Start.
Tests: 244 passed / 246 (2 pre-existing: AudioPipeline gains-mute, RoundClip).
Build 0 warnings. Scope check clean.
Memory-map correction (derived-solution rule, 2026-08-29): image-shrink recipe was
never recorded when first done, so it was re-derived. Added Derived-solution/recipes
rule to AGENTS.md; MyMistakes.md now a permanent recipes registry (records the
verified WPF-imaging shrink recipe); schema.md rows MyMistakes as registry; ai.md
points to the rule. README hero image replaced: 3.2MB screenshot -> 1400x794 ->
188KB docs/ytLlive-preview.jpg (JPEG q82).
gramps