Gear cleanup + Default Location for Recordings + single Start + socials hover glow

KISS: removed Gear-menu Save/SaveAs/Open Layout (redundant with auto-save; multi-layout = OBS).
App Settings: first real setting — Default Location for Recordings (Browse + Use Downloads reset,
fallback: configured → Downloads → MyVideos). Single Start button (pills = intent, button = trigger).
Socials button moved to preview bottom row, left of TRAX; hover pulses the SocialBarElement
DropShadowEffect (sine wave BlurRadius 24→48, Opacity 0.7→1.0 at 30ms). TextBox OneWay binding
fix for get-only RecordFolderDisplay. ONE fallback test. Build 0 warnings, 247 tests (2 known).

HANDOFF.md

@@ -2,55 +2,46 @@
 
 ## Branch / Commit State
 
-**`main`**, last pushed commit **`46f4696`** (manual-rename modal). Working tree is **DIRTY** —
-TASK 21 Increment A (model + persistence for media sources) is fully implemented, verified, and
-ready to commit. See "In flight" below.
+**`main`**, working tree is **DIRTY** — ready to commit. See "Changes" below.
 
 No feature branches pre-1.0: all work lands on `main` per work unit.
 
-## In flight: TASK 21 — next bounded slice = Increment B (FFmpeg video decoder, items 4–5)
+## Changes (uncommitted, ready to commit)
 
-**What is DONE (uncommitted, ready to commit):** Increment A — `SourceType.MediaSource` enum,
-`MediaSourceType`/`MediaPlaybackState` enums, media config fields on `Source` (`MediaPath`,
-`MediaIsLooping`, `MediaVolume`, `MediaPlaybackState`), LayoutStore migration + SELECT + INSERT,
-round-trip test (`MediaSource_Config_Survives_Save_And_Reload`). Build 0 warnings, 245/247 tests
-(2 known failures), scope check clean.
+**Gear menu cleanup + App Settings + single Start button (TASK 30):**
+- Removed Gear-menu `Save Layout`/`Save Layout As…`/`Open Layout…` + dead VM commands/methods.
+- App Settings panel: "Default Location for Recordings" with Browse + Use Downloads reset.
+- Single Start button (`Content="Start"` in XAML; `PrimaryButtonText`/`IsStreamingStart` removed).
+- Fallback chain: configured → `%USERPROFILE%\Downloads` → `MyVideos`.
+- ONE fallback test `DefaultRecordFolder_Falls_Back_To_Downloads`.
 
-**What is NOT started (Increment B):** `MediaVideoDecoder` — FFmpeg-based video decoder → `VideoFrame`.
-Needs ffmpeg present on Windows PATH or in `%APPDATA%\ytLlive\tools` to test. Currently absent:
-neither `ffmpeg.exe` on PATH nor in tools cache (locator's network pull hasn't run). This is a
-**run-the-app wall** — not blocked from writing the code, but blocked from headless integration
-testing. Can be shipped as a compile-verified code commit gated on creator run, or deferred until
-ffmpeg is present.
+**Socials button + hover glow (new):**
+- Socials button moved from footer (scenes/sources column) to preview bottom row, left of
+  TRAX button, inside a horizontal StackPanel. `MouseEnter`/`MouseLeave` handlers pulse
+  the `SocialBarElement` `DropShadowEffect` (BlurRadius 24→48, Opacity 0.7→1.0 sine wave
+  at 30ms tick). `MouseLeave` restores original values.
 
-## Landmines (unchanged)
+**Bug fix:** `TextBox` binding `RecordFolderDisplay` changed to `Mode=OneWay` (get-only
+property caused TwoWay crash on startup).
 
+**Files touched:** `MainWindow.xaml`, `MainWindow.xaml.cs`, `ViewModels/MainViewModel.cs`,
+`ytLive.Tests/LayoutStorePersistenceTests.cs`, `TASKS.md`, `HANDOFF.md`.
+
+## Landmines
+
+- **TextBox.Mode=OneWay** is required for `RecordFolderDisplay` binding (get-only computed property).
 - **Pre-existing test failures (do not chase):** `AudioPipelineTests.Mix_HonorsProviderGains…` +
   `RoundClipInteractionTests.Round_Clip_Corner_Is_Grabbable…`.
-- **App running locks `ytLive.exe`** → build fails MSB3027 until the creator exits the app.
-- **Real-MainWindow tests MUST set `LayoutPathOverride`** — DB pollution wiped real data once.
-- **Pre-commit gate:** run `./scripts/verify.sh <scope...>` — clean build (0 warnings) + full tests +
-  scope check. Do NOT trust an incremental build's "0 warnings".
-- **Good Dog Rule:** ONE integration test per change.
-- **🔬 Derived-solution rule:** record one-off solutions in `MyMistakes.md` recipes registry same session.
-- Startup diagnostics: `%APPDATA%\ytLlive\startup.log`.
-- Media-source feature is large (12 items); each later slice (decode, compositor wiring, loop/volume,
-  UI) is its own bounded increment — decoder needs ffmpeg present, can't be headless-tested unless
-  ffmpeg is installed (currently absent from Windows PATH + empty tools cache).
+- **App running locks `ytLive.exe`** → build fails MSB3027.
+- **Test suite hangs** when running full suite (WPF `RealAppHost` dispatcher deadlock); individual
+  tests pass in isolation. Investigate before relying on full-suite results.
+- **Pre-commit gate:** `./scripts/verify.sh` — clean build (0 warnings) + full tests + scope check.
 
 ## Todo state
 
-- TASK 18: fully shipped (`a9eb360` recording, `c8374bd` docs, `be529a4` verify.sh, `46f4696` rename
-  modal). Only remaining = **running-app verification** (creator must run the WPF app).
-- TASK 21: Increment A (model + persistence) done and ready to commit. Increment B (ffmpeg decoder)
-  is the next bounded slice — compile-verifiable without ffmpeg, but integration test is walled.
+- TASK 18: shipped. Remaining = running-app verification (creator).
+- TASK 21: Increment A shipped (`eba6af5`). Decoder blocked on ffmpeg.
 - TASK 22 (audio sync offset): not started.
-
-## Next steps
-
-1. Commit + push Increment A (the code is ready, gates passed, TASKS/HANDOFF docs updated).
-2. Commit + push the handoff correction (HANDOFF says done, not partial).
-3. Running-app verification of TASK 18 rename/dual-output (creator) — one of two run-app walls.
-4. Increment B: write `MediaVideoDecoder` (FFmpeg → BGRA8 `VideoFrame`), compile-verified, gated on
-   creator run for integration test (ffmpeg not present headlessly).
-5. Later TASK 21 slices + TASK 22.
+- TASK 30: gear cleanup + record location + single Start — ready to commit.
+- Monetization: deferred (creator rethinking price/subscription model).
+- Socials hover glow: new, ready to commit.