Transitions: fade starts from the outgoing picture (was an instant cut)

The transition started with no from-frame, so BlendFrame returned the new scene at once.
Start now requests a capture and the frame pump supplies its last output on the next tick.
Test: TransitionFadeTests. Docs: ai.md, TASKS.md.

Not pushed.

TASKS.md

@@ -451,3 +451,14 @@ These were explicitly ruled out:
 - **OBS-style source expansion** (game capture, browser source, media playlist, VLC, color-key, MIDI — the minimal source set is deliberate; creators who need more have graduated to OBS)
 - **Multi-layout** (auto-save, single layout; multi-layout = OBS territory)
 - **Cross-process stream resume** (API makes it impossible; creator ruling 2026-09-01)
+
+## Transitions & brand logo (queued 2026-10-27)
+
+- ✅ **Fade fix** — swaps fade from the outgoing picture (`TransitionFadeTests`). On-screen check pending.
+- ☐ **Transition picker** in App Settings (type + duration).
+- ☐ **Wipe** — CPU blend, direction setting.
+- ☐ **Move** — persistent layers (per-layer "carry across scenes" flag), per-scene placement, fixed z band.
+- ☐ **Brand logo** — permanent "Brand logo" layer above background in every scene; file in App Settings
+  (imported to the asset table); per-scene eye toggle; top-left default.
+- ☐ **Cube** — GPU path gated on capability; CPU path only if it holds 60fps.
+- Gear: right-click opens App Settings (built, on-screen check pending). Left-click menu stays for now.