Webcam resource validation + first-frame proof + CameraConflictProbe: MediaCaptureFrameSource validates post-init (VideoDeviceId match, stream properties, reader StartAsync status), subscribes Failed/CameraStreamStateChanged → SourceFailed; CameraManager.AcquireAsync requires first-frame proof (4s timeout) — silent empty box impossible; MainViewModel surfaces WebcamError chip + MessageBox with suspect-app names; fallback ladder VideoPreview → VideoRecord; 19041 SDK projection gaps documented; AGENTS.md + schema.md + HANDOFF.md memory-map rules added; 81 tests passing, 0 warnings

schema.md

@@ -20,6 +20,7 @@ that every other memory file follows. Read `ai.md` first; this file explains
 | `README.md` | Human-facing intro: what the app is, how to run it, roadmap | no |
 | `ai.md` | **AI guide + session handoff** — architecture, patterns, decisions, the cognitive map home | **yes — start here** |
 | `TASKS.md` | Task queue + authoritative YouTube API research facts + task statuses | yes — for status |
+| `HANDOFF.md` | Current operational state: what's in flight, landmines, next step, secret/DB/port locations | yes — trust it as current state |
 | `schema.md` | This file: the conventions below | when in doubt |
 | `<dir>/index.md` | Per-directory map (progressive disclosure): what lives there + links | when diving into code |
 | `Views/` | Reserved for Views; currently empty | — |