LlamaCasty/ViewModels/index.md

# ViewModels — index

MVVM layer. See [`schema.md`](../schema.md) for the memory-map conventions.

Each landed `MainViewModel` partial owns a row here describing its area; the
`MainViewModel.cs` row describes only what still lives in core. Docking most
areas' docs in their own rows keeps this index small to read.

| File | Purpose |
|------|---------|
| `MainViewModel.cs` | Core. `public partial class MainViewModel : ViewModelBase`. **Source commands + element rows:** scenes are pure selection rows; sources carry edit/visibility/trash (`EditElementCommand` sets `element.IsEditing`, `ToggleElementVisibilityCommand` flips `IsVisible`, `RemoveSourceCommand`; Backdrop trash slot reserved via `HiddenBoolToVisibilityConverter` — TASK 13); shared `NextSourceName` (Image, Image2, Image3… no-space increment from actual names — used by `AddSource` + `AddReusedImage`), `AddImageCommand`. **Lifecycle/ctor wiring:** fields + ctor wiring (all command assignments, mixer/camera/chat/hotkey/subscription hookups), `Shutdown`/`SaveLayoutNow`/`ScheduleSave`/`LoadLayout`, `CreateBrush` + shared `BarOnBrush`/`BarOffBrush` (referenced by Audio/Trax/Socials partials), window-geometry pass-through, `SelectedElement`/`OnSelectedElementPropertyChanged` (the selection change also raises `CanToggleClipShape` — TASK 57), `ShowPreviewPlaceholder`, `BrandFlash*`, WebView2 hosting (`InitWebView2`/`RegisterLoadedWebSources`/`OnWebView2PreviewBitmapChanged`), frame-pump wiring (construction + `_rtmpUrlProvider` seam + `Dispose`, plus `ResolveOutputFrame` → cached TextOverlay frame / `RenderChatBox` / `RenderAlertBox` for text, chat, and alert layers) — the pump's stream-state consumers live in the Streaming partial. |
| `MainViewModel.Account.cs` | Session + connected account: `LoadSavedSessionAsync` (DPAPI restore at startup), `SignInAsync`/`ChangeAccountAsync`/`SignOutYouTubeAsync`, `IsConnected`/`AccountAvatarUrl`/`AccountDisplayName`/`AccountStatusLightToolTip` via `SyncConnectedAccount` (cleared on End). |
| `MainViewModel.License.cs` | Polar license (freemium): `LicenseKey`/`LicenseMessage`/`IsLicenseValidating`/`IsLicenseEntryOpen`/`IsHubVisible`/`IsPremium`, `OfflineGracePeriod`, `ValidateLicenseAtStartupAsync`/`ActivateLicenseAsync`. |
| `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`. **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`; the Chat scene's own rules (Unit 2) — `IsChatSceneCamera`/`CanToggleClipShape` (the circle is NOT offered in the vertical Chat layout) and `ResizeWebcamInVerticalTier` (the Chat camera's two sizes, then the snap; the Live camera resizes freely inside the band) |
| `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; **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`. **TASK 57 (Unit 2):** the tier change also raises `CanToggleClipShape` (the circle option disappears in the vertical Chat layout). |
| `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), `ShowAbout` (returns to the About hub) + `ShowLicenses` (loads shipped `THIRD-PARTY-NOTICES.txt` into `LicensesText` in-app); bug/feature report `BugReportText`/`BugReportEmail`/`FeatureRequestText`/`FeatureRequestEmail` + `SubmitBug`/`SubmitFeature`/`ComposeEmail`/`OpenUrl`; About hub consts `ChannelUrl`/`MastodonUrl`/`CoffeeUrl` + `PremiumUrl` (`https://llamacasty.com`, opens only when explicitly clicked) + `IsPremiumAvailable` + `SupportEmail` + `AppVersionLabel`; commands `OpenSettingsCommand`/`OpenBugCommand`/`OpenFeatureCommand`/`OpenAboutCommand`/`CloseOverlayCommand`/`SubmitBugCommand`/`SubmitFeatureCommand`/`OpenChannelCommand`/`OpenMastodonCommand`/`OpenCoffeeCommand`/`OpenPremiumCommand`/`OpenLicensesCommand`. A locked quality selection opens About without changing the tier. 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. |
| `MainViewModel.Logs.cs` | Non-edit left-panel tab state and bounded current-launch log collections; refreshes the process-local AppLog snapshot while Logs is selected, pins Class 1 before Class 2 until acknowledged, then returns entries to the LIFO timeline; stops its dispatcher timer on shutdown. |
| `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 |
| **About hub (TASK 11, in `MainViewModel.Overlays.cs`)** | the About overlay is the in-app creator hub: `ChannelUrl`/`MastodonUrl`/`CoffeeUrl` (public consts, live) + `PremiumUrl` (tabled billing seam — TASK 12 → the greyed "Unlock Premium" button lights up when filled); `OpenLicensesCommand` → `ShowLicenses()` loads the shipped `THIRD-PARTY-NOTICES.txt` into `LicensesText` and sets `IsLicensesOpen` (in-app scrolling panel, never the OS viewer); `BackToAbout_Click` in `MainWindow.xaml.cs` flips it off. |
| `ReuseImageViewModel.cs` | Add Image dialog: candidate list (`ReuseImageCandidate`), reuse/new/cancel |
| `CameraPickerViewModel.cs` | Add Webcam dialog: async camera list (loading / has / none states), `UseRequested(CameraDeviceInfo)`/`CancelRequested` |
| `MicPickerViewModel.cs` | Select Microphone dialog (voice source): async mic list (loading / has / none states), `UseRequested(MicrophoneDeviceInfo)`/`CancelRequested` |
| `SocialsDialogViewModel.cs` | Social Media Site Promotion dialog (six fixed slots, `SocialSlotViewModel`): row 0 = YouTube sign-in gate (sign-in provider fills the channel, delete = sign-out); rows 1-5 validated entries / empty / freemium locks 2-5 (`isPremium` seam); `DetectService` → `ISocialValidator` on confirm (input snaps to text + real logo on success, red do-not + stays editable on failure); `CanSave` blocked while any slot edits/validates/errors; `BarEnabled` switch; commit via `CommittedEntries` + `BuildSocialsConfig()` (YouTube first) + `SaveRequested`/`CancelRequested`. WPF-free — the window owns the dialogs (delete confirm, sign-in gate) and calls `StartEdit`/`ConfirmEdit`/`DeleteSlotAsync`. |

| `MainViewModel.Sources.cs` | Source creation/removal; `AddSource` creates the standalone ticker layer with one-per-scene gating and its 1920×48 default geometry; TextOverlay starts as a visible 900×140 draggable text layer. |
| `MainViewModel.TextOverlay.cs` | Raster-on-change TextOverlay preview hookup and settings/dimension invalidation; output resolution reads its immutable cached frame. |
| `MainViewModel.AlertTicker.cs` | AlertBox ticker preview routing: selects the preview scene's AlertBox settings and publishes the positioned box-sized frame to PreviewPane. |

Related: [`Models/index.md`](../Models/index.md) for the data; [`Services/index.md`](../Services/index.md)
for what the ViewModels drive; base class in [`Helpers/ViewModelBase.cs`](../Helpers/ViewModelBase.cs).

## MainViewModel partial split (in progress)

`MainViewModel.cs` is being split into one file per functional area, zero behavior
change, one commit per partial (each commit a roll-back point). **Commit naming:**
titles carry the series id (`Commit N/12`), tags are `refactor-commit-N` — e.g.
`git show refactor-commit-1`. Every partial lands with a `ViewModels/index.md`
update in the SAME commit. Each partial's docs live in its table row above; this
tracker is just the code↔commit map.

Progress (Commit N/12 · tag):
- [x] **Commit 1/12 · `refactor-commit-1`** — **Account** → `MainViewModel.Account.cs`
- [x] **Commit 2/12 · `refactor-commit-2`** — **License** → `MainViewModel.License.cs`
- [x] **Commit 3/12 · `refactor-commit-3`** — **Scenes** → `MainViewModel.Scenes.cs`
- [x] **Commit 4/12 · `refactor-commit-4`** — **Background** → `MainViewModel.Background.cs`
- [x] **Commit 5/12 · `refactor-commit-5`** — **Webcam** → `MainViewModel.Webcam.cs`
- [x] **Commit 6/12 · `refactor-commit-6`** — **Audio** → `MainViewModel.Audio.cs`
- [x] **Commit 7/12 · `refactor-commit-7`** — **Trax** → `MainViewModel.Trax.cs`
- [x] **Commit 8/12 · `refactor-commit-8`** — **Socials** → `MainViewModel.Socials.cs`
- [x] **Commit 9/12 · `refactor-commit-9`** — **Streaming** → `MainViewModel.Streaming.cs`
- [x] **Commit 10/12 · `refactor-commit-10`** — **Chat** → `MainViewModel.Chat.cs`
- [x] **Commit 11/12 · `refactor-commit-11`** — **Overlays** → `MainViewModel.Overlays.cs`
- [x] **Phase 1 complete:** core `MainViewModel.cs` split into 10 functional partials (1,890 → 758 lines).

**Phase 2 — `MainWindow.xaml` split into UserControls** (new `Controls/` folder, namespace `ytLive.Controls`):
- [x] **Commit 12 · `refactor-commit-12`** — **BottomBar** → `Controls/BottomBar.xaml(.cs)` (gear menu + stream stats + quality dropdown; `GearButton_Click` moved to the control's code-behind).
- [x] **Commit 13 · `refactor-commit-13`** — **HealthBanner** → `Controls/HealthBanner.xaml` (Row 1). Also promoted the 7 value↔visibility converters out of `MainWindow.Window.Resources` into `Themes/Controls.xaml` so extracted controls can resolve them (app-level, not window-level).
- [x] **Commit 14 · `refactor-commit-14`** — **TopBar** → `Controls/TopBar.xaml(.cs)` (Row 0: logo, REC/ON-AIR pills + signs, avatar, Sign In/Start/End buttons). Avatar fetch moved (async-preserved) into the control; window exposes `_topBar.RefreshAvatar()` invoked on `IsConnected`/`AccountAvatarUrl` changes.
- [x] **Commit 15 · `refactor-commit-15`** — **PreviewPane** → `Controls/PreviewPane.xaml(.cs)` (Row 1 Col 1 center preview pane). Moved the 1920×1080 canvas (OverlayCanvas/SelectionOverlay/BrandFlashLayer/SocialBarElement), text pull-out, and the live-controls row (TRAX/game/mic meters + sliders + speakers + socials button). Code-behind moved: preview drag/select/resize/hit-test (Preview_Mouse*, HitHandle, HitElement), webcam-context-menu handlers (WebcamMenu_*), social-bar glow (SocialBar_*, SocialsButton_*, SocialGlowTick), audio sliders/speakers (VolumeSlider_*, GameVolumeSlider_*, MicSpeaker_*, GameSpeaker_*, SetSliderValueFromClick, FindParent), TraxButton_*. Window keeps the source-list left panel + thumbnail strip + edit UI, and routes selection-overlay via `_previewPane.UpdateSelectionOverlay(bool)` plus `_previewPane.IsClickInsidePreview/Drawer`. `BackgroundMenu_*` stayed in the window (used by the left-panel source context menu).
- [x] **Commit 16 · `refactor-commit-16`** — **SceneThumbnailStrip** → `Controls/SceneThumbnailStrip.xaml(.cs)` (Row 0 scene-picker strip). `Thumbnail_MouseLeftButtonDown` moved into the control (transitions via `DataContext.TransitionToScene`).
- [x] **Commit 17 · `refactor-commit-17`** — **LeftPanel** → `Controls/LeftPanel.xaml(.cs)` (Row 1 Col 0 left panel: layers/properties edit UI + live chat list). Moved ALL property-editor and chat handlers: `SourceNameBox_*`/`CommitSourceEdit`, `AddSourceButton_Click`, `OnChatMessagesChanged` (now self-subscribed on Loaded), `MirrorButton_Click`, `ShapeButton_Click`, `SourceMenu_Remove`, `BackgroundMenu_*`, `OpacitySlider_ValueChanged`, list drag-to-reorder (`_dragStartPoint`+`List_Preview*`+`EndListDrag`+`FindItemContainerAt`), and the snapshot family (`TakeSnapshot`, `WebcamBorder*`, `Countdown*`, `Web*`). Window exposes via `_leftPanel.IsClickInside(original)` (deselect guard) and `_leftPanel.OnSelectionChanged(vm)` (opacity label + snapshot). Pending: overlay host region.
- [x] **Commit 18 · `refactor-commit-18`** — **OverlayHost** → `Controls/OverlayHost.xaml(.cs)` (settings/bug/feature/about dialogs). `BackToAbout_Click` moved with it (uses inherited `DataContext`). Window keeps the thin `WebViewHostPanel` + `ToastArea` root stubs so name lookups are untouched (WebView2 ctor init, `NotificationService.InArea("ToastArea")`) — toast/WebView2 behavior unchanged. **Phase 2 COMPLETE** — MainWindow.xaml carved down to a 123-line shell over 6 controls (TopBar, HealthBanner, BottomBar, SceneThumbnailStrip, LeftPanel, PreviewPane, OverlayHost). Pending: session wrap-up (HANDOFF.md) + push on approval. *(The `WebViewHostPanel` root stub is since GONE — the 2026-09-14 composition-capture redesign moved `InitWebView2()` to `MainWindow_Loaded` and deleted the panel; see `Controls/index.md`.)*

**Phase 3 — 500-line compliance (production `.cs` only).** Bring all production
source files under 500 lines. One roll-back commit per file; same drill
(0-warning build, `verify.sh` 246+2, explicit-file scope-check, tracker in same
commit, tag `refactor-commit-N`, no per-commit push).
- [x] **Commit A · `refactor-commit-A`** — **core** → `MainViewModel.cs` 758 → **495**. Moved source add/remove/image block to new **`MainViewModel.Sources.cs`** (234 lines: `AddSource`, `NextSourceName`, `AddImage`, `BuildImageCandidates`, `PickImageBytes`, `AddAsset`, `AddImageSource`, `AddReusedImage`, `RemoveElement`) and WebView2 hosting (`RegisterLoadedWebSources`, `InitWebView2`, `OnWebView2PreviewBitmapChanged`) to new **`MainViewModel.Web.cs`**. Pruned now-dead usings (`Microsoft.Win32`, `NAudio.CoreAudioApi`, `System.Windows.Media.Imaging`, `Collections.ObjectModel/Specialized`). Pending: Streaming, Background, SocialsDialogViewModel, LayoutStore.
- [x] **Commit B · `refactor-commit-B`** — **Streaming** → `MainViewModel.Streaming.cs` 789 → **330** + new **`MainViewModel.Streaming.Operations.cs`** (459 lines). Moved the go-live/record/health operation bodies (`StartSession`, `BeginRecordOnly`, `BeginGoLive`, `StartRecordFile`, `PrepareAndStartLiveAsync`, `PollHealthAsync`/`OnHealthPollTick`/`ApplyHealthIssue`, `StopStream`, `FinalizeRecordingAsync`, `UniquePath`, `ChooseRecordFolder`, `ResetRecordFolder`, `DefaultRecordFolder`, `OnFramePumpFailed`, `OnFramePumpHealthUpdated`, `ApplyHealth`, `ResetHealth`, `BuildEncoderOptions`) into the Operations partial; Streaming.cs keeps state + quality/resolution tiers + session timer + command declarations. Pruned dead usings both files. Pending: Background, SocialsDialogViewModel, LayoutStore.
- [x] **Commit C · `refactor-commit-C`** — **Background** → `MainViewModel.Background.cs` 567 → **418** + new **`MainViewModel.Background.Model.cs`** (163 lines). Moved the static scene-model helpers (`LoadBackgroundImage`, `CreatePlaceholderSnapshot`, `EnsureBackground`, `CreateBackground`, `NormalizeBackgrounds`, `AllBackgrounds`, `ResolveAutoCaptureKey`, `MonitorKeyPrefix`) into the Model partial; Background.cs keeps capture/live state + operations (`UpdateActiveBackground`, `UpdateBackgroundImage`, `RefreshSnapshotsAsync`, `ReacquireScreenCaptures`, `OnScreenPreviewBitmapChanged`, `OnFullscreenMonitorChanged`, `RefreshBackgroundAutoCapture`, `BrowseBackground`, `ClearBackgroundCaptureAsync`, `RedesignateBackgroundAsync`, `ChangeBackgroundCaptureAsync`, `SetBackgroundCapture`, `DefaultBackgroundAsset`, `HealBackgrounds`, `StampDefaultBackgroundAsset`). Pending: SocialsDialogViewModel, LayoutStore.
- [x] **Commit D · `refactor-commit-D`** — **SocialsDialog** → `SocialsDialogViewModel.cs` 515 → **334** + new **`SocialSlotViewModel.cs`** (183 lines). Moved the `DialogEntry` record + the row-level `SocialSlotViewModel` (six-fixed-slot row VM: service/logo/lock/edit/validate state + computed `Show*` flags) into its own file; `SocialsDialogViewModel.cs` keeps the dialog VM (sign-in gate, validation orchestration, commit). `DialogEntry` stays `public` in the same namespace so both files see it. Pending: LayoutStore.
- [x] **Commit E · `refactor-commit-E`** — **LayoutStore** → `LayoutStore.cs` 1402 split into 6 concern-based partials: **`LayoutStore.cs`** (47: shell — `Instance`, fields, ctor + `EnsureSchema`, `GetUserVersion`, `Dispose`), **`LayoutStore.Migrations.cs`** (495: all `Migrate*` + `EnsureSchema`), **`LayoutStore.Load.cs`** (221: `Load`), **`LayoutStore.Save.cs`** (339: `Save`), **`LayoutStore.Settings.cs`** (292: mic/record-folder/reusable-stream + license/transition/broadcast/hotkey/window `GetSetting`/`UpsertSetting`), **`LayoutStore.Assets.cs`** (41: `GetAssetBytes`/`UpsertAsset`). **PHASE 3 COMPLETE — no production `.cs` over 500.**
- [x] **Commit F · `refactor-commit-F`** — **Recording (context/concern)** → new **`MainViewModel.Recording.cs`** (121 lines). The encoder (`Services/Encoder/FfmpegEncoder.cs`) and frame pump (`Services/Encoder/FramePump.cs`) were ALREADY extracted services — the planned "extract FFmpegEncoder/StreamHealthMonitor/FramePump" was a no-op premise. The honest functional seam was the local recording-output concern: `StartRecordFile`, `FinalizeRecordingAsync`, `UniquePath`, `ChooseRecordFolder`, `ResetRecordFolder`, `DefaultRecordFolder` + fields `_recordFolder`/`RecordFolderDisplay`/`_activeRecordPath`/`_recordStartTime`/`_recordLength` moved out of the live-stream orchestration. `MainViewModel.Streaming.Operations.cs` 475 → **377**; `MainViewModel.Streaming.cs` 328 → **323**. Same partial class, MVVM glue untouched.
- [x] **Commit G · `refactor-commit-G`** — **ChatOverlayLayer (true component)** → new **`Services/ChatOverlayLayer.cs`** (199 lines). The first REAL decomposition of the 4,105-line god-object: `MainViewModel.Chat.cs` 194 → **44** (thin delegation). The layer owns all chat behavior — `Messages` buffer, `ChatBoxRenderer`, fade timer, mock-preview timer, per-source preview renders, live-output `RenderFrame`. The VM keeps only the binding surface: `ChatMessages` (delegates to `_chatLayer.Messages`, so XAML bind + LeftPanel `CollectionChanged` hold), `CanAddYouTubeChat`/`ShowChatInactiveMessage` (computed + `OnPropertyChanged` from VM setters), and thin forwards. Scenes are handed in as args (no `Func` seam) so the layer stays scene-graph-free. Zero behavior change; 246 pass / 2 known.
The partial `.cs` files land next to `MainViewModel.cs` in this folder as the split
proceeds; each partial carries its own `using`s and re-declares nothing from core.