feat(ui): TASK 42 top bar redesign — one Record-or-Stream surface (2026-09-22)

The bar now renders ONE surface from the FIRST decision the creator makes —
Record or Stream — with each world being the whole bar. Creator directive:
"I wrote the fucking thing and I still can't figure-out how to do stuff",
"forget this one dog plan bullshit". OBS/streaming-tool reference for the
one-surface paradigm: https://obsproject.com (single mode toggle + context
actions) — cited per spin-guard habit; the go-live/test pattern follows
CEV (https://cev-desktop.aSean.xyz) precedent.

- Mode: single segmented REC|ON-AIR switch (SegmentToggle/SegmentLabel in
  Themes/Controls.xaml); radio-exclusive world selection, one tap to flip.
- Record world: switch + Start Recording, zero YouTube identity.
- Stream world: switch + Go Live + Test + account zone right (Sign In until
  connected, then avatar with Change Account/Logout context menu).
- Test is a child of Stream: procs only stream-armed AND signed-in.
- Running: one reality line "dot word elapsed" (REC/LIVE/TEST; green/red/
  gold) + End; worlds + switch retire.
- Gear moved up from bottom bar, ~3 wordmark letters past the brand, single
  click opens Settings/Bug/Feature/About menu (TASK 40 Unit B shipped early).
- Fix folded in: BeginTestStream now arms OnAirPillOn explicitly (unarmed
  pump booted with zero encoder outputs -> "At least one output is required"
  forced-stop cascade from TASK 41's pipeline).
- VM: world/reality props + RaiseTopBarModes() wired into StreamStatus,
  pill, IsRecording, IsTestStream, IsConnected setters.

Doc: ai.md top-bar model, ViewModels/index.md, Controls/index.md, TASKS.md,
HANDOFF.md, new TASKS/task-42-top-bar-redesign.md; task-40 note.

Tests: TopBarModeTests.cs (new Good Dog), PillRadioTests + TestStreamTests
gates updated. Build 0 warnings; full suite 314/315 — single abort is the
pre-existing env-dependent RealMouseDrag test (Path of Exile 2 running)

TASKS/task-40-app-settings-round.md

@@ -91,12 +91,21 @@ drives `CameraConfigViewModel` — Auto + slider changes forward to the probe.
 
 ## Unit B — gear to top-left (your ask 2)
 
+> ✅ **SHIPPED 2026-09-22** as part of TASK 42 (top bar redesign) — gear is top-right
+> of the brand on `Controls/TopBar.xaml`, single click opens the Settings/Bug/Feature/
+> About menu (`GearButton_Click` moved from BottomBar). See
+> [`task-42-top-bar-redesign.md`](task-42-top-bar-redesign.md).
+
 - `Controls/TopBar.xaml`: `IconButton` gear **right of the brand Button**, gap ≈ 3 wordmark
   letters; left-click `OpenSettingsCommand`; ContextMenu keeps Report Bug / Feature
   Request / About. Remove the gear (+ its click handler) from `Controls/BottomBar.xaml(.cs)`.
 - Bonus: TopBar sits inside the overlay scrim span (`OverlayHost Grid.RowSpan=3` covers rows
   0–2), so the gear is correctly covered while an overlay is open — today it sits below the scrim.
 
+> **Left as follow-ups** (not part of the shipped gear): the overlay scrim row-span bonus (still
+> open) — the new gear sits in `OverlayHost`'s Row 0 but the scrim rows are not yet spanned over
+> it. Revisit when rows are next touched.
+
 ## Unit C — the small defaults (your ask 3, rest)
 
 - **Default output resolution** — persist `SelectedQuality` (e.g. Settings key