vv webcam Unit 1: the vertical (9:16) tier keeps its OWN camera placement per scene

The vertical tier is a centred band crop of the SAME 1920x1080 master (band x
656.25, w 607.5, h 1080), so the 16:9 camera placement (x~1408) falls outside the
cropped window and the creator is simply not in the vertical stream. Each scene
now keeps its own vertical position, size and shape; switching back to 16:9
restores the desktop layout exactly (the creator's locked table, 2026-10-17).

Geometry only - NO render-path change. The preview and the compositor both read
the element's own X/Y/W/H + ClipShape, so the tier switch swaps the LIVE geometry:
- Models/VerticalCameraLayout.cs (new): the pure math - the band, its two 607x540
  areas, the six spots (top/bottom x left/centre/right), the 32px inset and the
  270x152 default tile (480x270 in the 1080x1920 output) in the bottom-right spot,
  the corner the 16:9 default webcam uses.
- Models/WebcamSceneConfig.cs: the vertical placement lives in seven additive
  columns (VerticalX/Y/Width/Height/ClipShape/RectWidth/RectHeight; NULL = "this
  scene has no vertical placement yet"). The 16:9 layout stays in the old columns
  and is parked in the transient Landscape* fields while the vertical tier is
  live; Begin/EndVerticalLayout + CommitLiveLayoutToVertical do the swap. The
  X/Y/W/H overrides clamp every write into the band - outside it the camera is
  invisible in the vertical output.
- Models/SceneElement.cs: X/Y/Width/Height became virtual so the derived element
  constrains every writer (drag, resize handle, typed fields) in ONE choke point
  instead of three writers each re-implementing the rule.
- ViewModels/MainViewModel.Webcam.cs + .Streaming.cs: IsVerticalTier/VerticalBand,
  ResolveVerticalCameraLayout(s) (the tier swap), MoveWebcamInVerticalTier /
  SnapWebcamInVerticalTier (the six-spot snap, by the tile's centre),
  EnsureVerticalCameraLayout; ApplyStreamQuality is the tier-change hook. The
  Live scene gets its small tile automatically on the first vertical switch (the
  vertical stream would otherwise have no camera at all); the other scenes keep
  their 16:9 placement until the creator drags them into the band.
- Controls/PreviewPane.xaml.cs: the drag/resize route through the VM snap under
  the vertical tier instead of free-floating over the master.
  Controls/LeftPanel.xaml: the webcam properties gained a Geometry section
  (X/Y/W/H) for the manual entry the creator asked for, bound to the LIVE
  placement, gated on the VM's IsWebcamSelected (NOT SelectedElement.IsWebcam -
  the TASK 51 test finds that panel by binding text and would match twice).
- The store: seven guarded ADD COLUMNs, the INSERT/SELECT extended, and the
  X/Y/W/H/ClipShape columns stay the 16:9 layout - while the vertical tier is
  live the save writes the parked values there and the live ones into Vertical*.

Test: ytLive.Tests/VerticalWebcamLayoutTests.cs - the ONE Good Dog test. The
vertical tier brings the Live camera INTO the band as a small tile; dragging it to
the top-right lands it top-right inside the band; back to 16:9 the desktop layout
is restored exactly (1408/778/480x270); both placements survive a save + reload.
Full suite 429/429, 0 warnings. LayerReorderPersistenceTests.RealMouseDrag fails
ALONE on a clean tree in this environment - pre-existing flake, proven by stashing
this work, not a regression.

Derivative work: OBS has no built-in per-aspect-ratio layout storage - the
maintainers' answer is "create a second scene and add the scene you want to send
as source" (obsproject.com/forum/threads/161307) - and Streamyard's dual-aspect
guide says the same ("no built-in way to store separate layouts per aspect ratio",
so you rely on manual workarounds and plugins):
https://streamyard.com/blog/dual-aspect-ratio-streaming-tool
Our per-scene, per-tier stored placement, resolved on the tier change, is the
step past both.

Memory in the same commit: ai.md (new section), TASKS.md + TASKS/task-57-*.md
(Unit 1 shipped, Unit 2 = the Chat scene still open), HANDOFF.md, MyMistakes.md
(the per-tier geometry-swap recipe, the binding-text panel trap, the store's
webcam-identity rule) and the Models/Services/ViewModels/Controls index rows.

ViewModels/index.md

@@ -14,11 +14,11 @@ areas' docs in their own rows keeps this index small to read.
 | `MainViewModel.Scenes.cs` | Five-scene catalog: `Scenes` + `StagedScene`/`LiveScene`/`IsEditMode`, `AddScene` (canonical names only), `MissingScenes`/`ShowAddScene`/`AddSceneCommand`; scene wiring `OnScenesChanged`/`WireScene`/`UnwireScene`; transitions `SelectedTransitionType`/`TransitionDurationMs`/`TransitionToScene`/`ApplyTransitionToLive`; global hotkeys `HandleHotkey`/`OpenHotkeyConfig`/`RefreshHotkeyLabels`; scene-gating hints (`CanChangeBackground`). |
 | `MainViewModel.Zoom.cs` | **Zoom box (TASK 52, creator-corrected 2026-10-08)** `ActivateZoom`/`ToggleZoom`/`DismissZoom`/`StartZoomMove`/`UpdateZoomMove`/`EndZoomMove` + `RefreshZoomUi`/`RebuildDimRectsForZoom`. Right-clicking the live preview anchors a FIXED **capture window** (the box/2 region centred on the click) and parks a movable **2x magnifier**. The box shows a live always-on 2x view of the anchored capture; **dragging moves only the box — `CaptureX/Y` are deliberately untouched in `UpdateZoomMove`** (creator ruling). Each shape is centred on the click and clamped independently (box to the master, capture to box/2 windows): Circle = square, VerticalRectangle = 9:16, HorizontalRectangle = **4:3** (w=h·4/3 with h=0.7·1080; NOT 16:9 — first cut read as a square). The transient `ZoomSceneElement` mirrors box + capture; the output compositor draws it **LAST (layer n+1)** from the already-composed frame (`SceneCompositor.BlitZoom`→`ZoomMagnifier`) so it captures EVERY layer. No per-frame builder/cache — the resolver case that built `ZoomFrameBuilder` frames was removed. `BuildCompositorOptions` (internal = test seam) always returns the tier crop — the box is never the crop source. |
 | `MainViewModel.Background.cs` | Screen backdrop (Live-only by policy): `ScreenCaptureManager` + `ScreenCaptureSourceFactory` (WinRT GraphicsCapture); background model `EnsureBackground`/`CreateBackground`/`NormalizeBackgrounds`/`HealBackgrounds`/`StampDefaultBackgroundAsset`; screen capture `ReacquireScreenCaptures`/`ResolveAutoCaptureKey`/`RedesignateBackgroundAsync`/`ClearBackgroundCaptureAsync`/`SetBackgroundCapture`/`OnScreenPreviewBitmapChanged`/`OnFullscreenMonitorChanged`/`RefreshBackgroundAutoCapture`/`BackgroundShowDesktop` (keys on full-screen-game monitor or primary display via `Win32FullScreenDetector`); display picker `Displays`/`SetBackgroundDisplayCommand`; preview fns `ActiveBackgroundImage`/`BackgroundImage`/`UpdateActiveBackground`/`UpdateBackgroundImage`/`RefreshSnapshotsAsync`/`LoadBackgroundImage`/`CreatePlaceholderSnapshot`; `ChangeCaptureCommand`/`RefreshCaptureCommand`/`ToggleShowDesktopCommand`/`BrowseBackgroundCommand`. `ShowPreviewPlaceholder` stays in core. |
-| `MainViewModel.Webcam.cs` | Webcam identity: `_webcam`/`ReacquireWebcam`/`SwapWebcamIdentityAsync`; per-scene configs `AddWebcamToStagedSceneAsync`/`ShowWebcamInStagedScene`/`ChangeWebcamAsync` (Windows picker always opens); capture `OnCameraPreviewBitmapChanged`/`OnCameraFailed`; gating `CanAddWebcam`/`CanChangeWebcam`/`CanShowWebcamInStagedScene`/`IsWebcamSelected`/`WebcamError`; size safeguards `WebcamMax*`/`ClampWebcamToBounds`/`HealLegacySquareRect`; `AddWebcamCommand`/`ChangeWebcamCommand`/`ShowWebcamCommand`. |
+| `MainViewModel.Webcam.cs` | Webcam identity: `_webcam`/`ReacquireWebcam`/`SwapWebcamIdentityAsync`; per-scene configs `AddWebcamToStagedSceneAsync`/`ShowWebcamInStagedScene`/`ChangeWebcamAsync` (Windows picker always opens); capture `OnCameraPreviewBitmapChanged`/`OnCameraFailed`; gating `CanAddWebcam`/`CanChangeWebcam`/`CanShowWebcamInStagedScene`/`IsWebcamSelected`/`WebcamError`; size safeguards `WebcamMax*`/`ClampWebcamToBounds`/`HealLegacySquareRect`; `AddWebcamCommand`/`ChangeWebcamCommand`/`ShowWebcamCommand`. **TASK 57 (the "vv" feature):** the vertical (9:16) tier's camera placement — `IsVerticalTier`/`VerticalBand` + `ResolveVerticalCameraLayouts`/`ResolveVerticalCameraLayout` (the tier swap: the vertical tier brings each scene's own vertical placement in, the Live scene gets its small tile on first use, 16:9 puts the desktop layout back exactly) + `MoveWebcamInVerticalTier`/`SnapWebcamInVerticalTier` (the six-spot snap) + `EnsureVerticalCameraLayout`. |
 | `MainViewModel.Audio.cs` | **Mic bar:** read-only realtime meter `AudioLevel`/`MeterFillWidth`/`MeterBrush` (fill = `Math.Min(1, AudioLevelMeter.ToDisplay((float)AudioLevel) * MicVolume)`, green→yellow→red at 60%/80% zones), `MicVolume` (0.8 default; drives `MicMuted` ⇔ volume 0; unmute flash `BeginVolumeFlash`/`EndVolumeFlash`/`CancelVolumeFlash`), `MicSourceName` (left-justified inside the bar, persists via `LayoutStore.Settings`), `ToggleMicMute`/`PickMicrophone` (`MicPickerDialog`; picked device swaps the live source via `_audioMixer.RestartMic()`, loopback keeps running), status dot `MicStatus`/`MicStatusBrush`/`MicStatusToolTip` (`Models.MicStatus`: green Connected / yellow Problem / red no-device), capture starts once at startup (`StartMicCaptureAsync`) — NOT go-live. **Game audio bar:** overlaid bottom-center, always visible (show/hide gating removed 2026-08-15); `GameAudioLevel` (loopback via `OnLoopbackLevelChanged`), `GameAudioVolume`/`GameMuted`/`GameMuteText`/`ToggleGameMute`/`PushSystemVolume`, mirror volume flash `SetGameVolumeAdjusting`/`BeginGameVolumeFlash`/`EndGameVolumeFlash`/`CancelGameVolumeFlash`. Mixer handlers `OnMicLevelChanged`/`OnLoopbackLevelChanged`/`OnMicConnected`/`OnMicFailed`. |
 | `MainViewModel.Trax.cs` | Background music (TASK 9, rides the loopback into the stream): `_musicPlayer` (`MusicPlayer`), `IsMusicPlaying`/`TraxError`/`TraxDotBrush`/`TraxToolTip`, interaction `TraxLeftClick`/`TraxRightClick`/`PickTraxTrack`, playback `LoadTrax`/`PlayTrax`/`PauseTrax`/`OnTraxPlaybackEnded`/`RefreshTraxUi`, `UpdateTraxLocalGain` (mirrors the game bar's mute onto `MusicPlayer.LocalGain` so the track ducks/restores with desktop audio). |
 | `MainViewModel.Socials.cs` | Social bar (global resource, overlaid on every scene): `_socials`/`_socialBarFrame`/`_socialValidator` (`ISocialValidator`/`HttpSocialValidator`), `HasSocials`/`SocialBarVisible`/`SocialBarDotBrush`/`SocialBarGlowBrush`/`Socials`/`SocialBarTop`, `OpenSocialDialogCommand`/`OpenSocialDialog` (spawns `SocialsDialogViewModel` + window; saved copy replaces `_socials`), `NotifySocialsChanged`/`RenderSocialBarFrame` (`SocialBarRenderer` → immutable `_socialBarFrame` the frame pump reads), fediverse heal `HealFediverseSoftwareAsync` (static, test-facing) + `HealFediverseSoftwareInBackground`, bar edge toggle `SetSocialBarPosition`/`ToggleSocialBarPosition`. `BarOnBrush`/`BarOffBrush`/`CreateBrush` stay in core (shared tokens). |
-| `MainViewModel.Streaming.cs` | Go-live/record + health + quality tiers + session UI. **Stream state:** `StreamStatus`/`StreamVisibility` setters + `_streamStatus` field, `IsOffline`/`IsLive`/`IsLivePrivate`. **Go-live flow:** `StartSession` (routes by pill state) → `BeginRecordOnly` (signed-out local recording) or `BeginGoLive` (GoLive dialog → captures title/description/visibility + `BroadcastForm.CaptureGoLive` → `PrepareAndStartLiveAsync`: reusable stream → `CreateBroadcast` (stores `_currentBroadcastId`) → empty-metadata warn → chat poll start (liveChatId) → `_framePump.StartAsync()` + health poll; failures → `StreamStatus.Error`, never a crash); `StartRecordFile` (auto-named `ty-…-0000.mp4`) + `FinalizeRecordingAsync` (rename modal, `UniquePath`); `StopStream` (posts Offline, stops chat/audio pipe/pump, clears `_currentBroadcastId`; session/token deliberately NOT cleared — sign-out stays explicit). **Health:** `CurrentHealth`/`ResetHealth`/`ApplyHealth`/`OnFramePumpHealthUpdated` (marshal `FramePump.HealthUpdated` off the stderr thread), `PollHealthAsync`/`OnHealthPollTick`/`ApplyHealthIssue` (report-by-exception banner `HealthIssueBanner`/`HealthIssueBackground` via `StreamHealthReporter`). **Session timer:** `_liveTimer` (ctor-wired) `UpdateSessionTimer`/`OnLiveTimerTick`/`LiveElapsedText`/`_recDotPulse`. **Start/End UI:** mode switch `RecordPillOn`/`OnAirPillOn`, top-bar worlds (`ShowIdleWorld`/`ShowRecordAction`/`ShowStreamActions`/`ShowSignInButton`/`ShowAvatarButton`, reality line `RunningVisible`/`RunningText`/`RunningDotBrush`, Test gate `ShowTestButton`/`CanStartTest` — `RaiseTopBarModes()`), `ShowPrimaryStartButton`/`CanStartSession`/`ShowEndStreamButton`/`EndButtonText`, REC sign `RecDotBrush`/`RecTextBrush`/`RecDotOpacity`/`OnAirBrush`, live window tokens `WindowTitle`/`TopBarBackground`/`PreviewGlow*` via `UpdateLiveVisuals`; `ChooseRecordFolder`/`ResetRecordFolder`/`_recordFolder`/`RecordFolderDisplay`/`DefaultRecordFolder`. **Resolution dropdown:** `QualityOptions`/`SelectedQuality`/`ResolutionHelp`/`ApplyStreamQuality` + `OutputRect*`/`DimRects`/`IsOutputCropped`/`ResolutionBadgeText` over the 1920×1080 master. **Pipeline bits:** `_framePump`/`_liveTimer`/`_healthPollTimer` fields, `BuildEncoderOptions`. Commands `StartStreamCommand`/`EndStreamCommand`/`ChooseRecordFolderCommand`/`ResetRecordFolderCommand`. Broadcast pull-out: `CurrentBroadcastId`/`BroadcastForm`. |
+| `MainViewModel.Streaming.cs` | Go-live/record + health + quality tiers + session UI. **Stream state:** `StreamStatus`/`StreamVisibility` setters + `_streamStatus` field, `IsOffline`/`IsLive`/`IsLivePrivate`. **Go-live flow:** `StartSession` (routes by pill state) → `BeginRecordOnly` (signed-out local recording) or `BeginGoLive` (GoLive dialog → captures title/description/visibility + `BroadcastForm.CaptureGoLive` → `PrepareAndStartLiveAsync`: reusable stream → `CreateBroadcast` (stores `_currentBroadcastId`) → empty-metadata warn → chat poll start (liveChatId) → `_framePump.StartAsync()` + health poll; failures → `StreamStatus.Error`, never a crash); `StartRecordFile` (auto-named `ty-…-0000.mp4`) + `FinalizeRecordingAsync` (rename modal, `UniquePath`); `StopStream` (posts Offline, stops chat/audio pipe/pump, clears `_currentBroadcastId`; session/token deliberately NOT cleared — sign-out stays explicit). **Health:** `CurrentHealth`/`ResetHealth`/`ApplyHealth`/`OnFramePumpHealthUpdated` (marshal `FramePump.HealthUpdated` off the stderr thread), `PollHealthAsync`/`OnHealthPollTick`/`ApplyHealthIssue` (report-by-exception banner `HealthIssueBanner`/`HealthIssueBackground` via `StreamHealthReporter`). **Session timer:** `_liveTimer` (ctor-wired) `UpdateSessionTimer`/`OnLiveTimerTick`/`LiveElapsedText`/`_recDotPulse`. **Start/End UI:** mode switch `RecordPillOn`/`OnAirPillOn`, top-bar worlds (`ShowIdleWorld`/`ShowRecordAction`/`ShowStreamActions`/`ShowSignInButton`/`ShowAvatarButton`, reality line `RunningVisible`/`RunningText`/`RunningDotBrush`, Test gate `ShowTestButton`/`CanStartTest` — `RaiseTopBarModes()`), `ShowPrimaryStartButton`/`CanStartSession`/`ShowEndStreamButton`/`EndButtonText`, REC sign `RecDotBrush`/`RecTextBrush`/`RecDotOpacity`/`OnAirBrush`, live window tokens `WindowTitle`/`TopBarBackground`/`PreviewGlow*` via `UpdateLiveVisuals`; `ChooseRecordFolder`/`ResetRecordFolder`/`_recordFolder`/`RecordFolderDisplay`/`DefaultRecordFolder`. **Resolution dropdown:** `QualityOptions`/`SelectedQuality`/`ResolutionHelp`/`ApplyStreamQuality` + `OutputRect*`/`DimRects`/`IsOutputCropped`/`ResolutionBadgeText` over the 1920×1080 master; **TASK 57:** the tier change also resolves every scene's camera placement (the vertical tier brings the vertical placements in, 16:9 restores the desktop layout — see `MainViewModel.Webcam.cs`). **Pipeline bits:** `_framePump`/`_liveTimer`/`_healthPollTimer` fields, `BuildEncoderOptions`. Commands `StartStreamCommand`/`EndStreamCommand`/`ChooseRecordFolderCommand`/`ResetRecordFolderCommand`. Broadcast pull-out: `CurrentBroadcastId`/`BroadcastForm`. |
 | `MainViewModel.Overlays.cs` | Settings/bug/feature/about panels + creator-hub links: panel state `IsSettingsOpen`/`IsBugOpen`/`IsFeatureOpen`/`IsAboutOpen` (via `SetPanel` → `IsAnyOverlayOpen`), `IsLicensesOpen` (flips `IsHubVisible`), `OverlayTitle`, `ShowOverlay` (one-panel exclusivity) + `ShowLicenses` (loads shipped `THIRD-PARTY-NOTICES.txt` into `LicensesText` on first open, never the OS viewer); bug/feature report `BugReportText`/`BugReportEmail`/`FeatureRequestText`/`FeatureRequestEmail` + `SubmitBug`/`SubmitFeature`/`ComposeEmail`/`OpenUrl`; About hub consts `ChannelUrl`/`MastodonUrl`/`CoffeeUrl` (public, integration-test live) + `PremiumUrl` (tabled billing seam — TASK 12 → greyed "Unlock Premium" lights up when filled) + `IsPremiumAvailable` + `SupportEmail` + `AppVersionLabel`; commands `OpenSettingsCommand`/`OpenBugCommand`/`OpenFeatureCommand`/`OpenAboutCommand`/`CloseOverlayCommand`/`SubmitBugCommand`/`SubmitFeatureCommand`/`OpenChannelCommand`/`OpenMastodonCommand`/`OpenCoffeeCommand`/`OpenPremiumCommand`/`OpenLicensesCommand`. Ctor command assignments stay in core. |
 | `MainViewModel.Chat.cs` | Chat overlay + preview pipeline: `ChatMessages` (500-message cap; clear-on-fade), `OnChatMessageReceived` (marshal `_youtubeChat.MessageReceived` onto the dispatcher, switch previews mock→real, then feed **both** component layers), fade `_chatFadeTimer`/`ResetChatFadeTimer` (shortest `ChatFadeSeconds` across chat layers); live render `RenderChatBox` (called from `ResolveOutputFrame`, stays in core) + preview render `UpdateChatBoxPreview` (bitmap onto `chatBox.VideoImageSource`); mock preview `MockChatMessages`/`StartMockChatPreview`/`StopMockChatPreview`/`RunMockChatPreviewAsync`/`_mockChatCts`; `UpdateActiveChatBoxPreviews` (wires Chat* property-change subscriptions + first render); `CanAddYouTubeChat` (one-per-layout gate), `ShowChatInactiveMessage` (`!IsLive`). **Alerts (TASK 43):** same facade for the native alert box — `_alertLayer` (`AlertOverlayLayer`), `RenderAlertBox`/`UpdateAlertBoxPreview`, `UpdateActiveAlertBoxPreviews`, `CanAddAlerts` (one alert zone per layout). Ctor wiring (`MessageReceived` hookup, `new ChatBoxRenderer()`, `new AlertRenderer()`, `LoadLayout` preview start, `_youtubeChat.Dispose` + `_alertLayer.Dispose`) stays in core. |
 | `GoLiveViewModel.cs` | Start Stream dialog: **account row** (saved channel shown with Change Account, or Sign in to YouTube; Start gated on `IsSignedIn`/`IsBusy`) + title/description + **locked Visibility (always "Private" — ship step 7, no dropdown)**, start/cancel requests |