refactor: split MainViewModel.Background under 500 lines — 500-limit Phase 3, Commit C

Background.cs 567 -> 418. Moved the static scene-model helpers
(LoadBackgroundImage, CreatePlaceholderSnapshot, EnsureBackground,
CreateBackground, NormalizeBackgrounds, AllBackgrounds, ResolveAutoCaptureKey,
MonitorKeyPrefix) into a new MainViewModel.Background.Model.cs partial.
Background.cs keeps capture/live state + operations.

Zero behavior change; build 0 warnings; 246 pass, only the 2 known failures.
Docs: ViewModels/index.md Phase 3 tracker updated in same commit.

Controls/index.md

@@ -0,0 +1,58 @@
+# Controls — index
+
+The phase-2 carved pieces of what used to be one monolithic `MainWindow.xaml`
+(1,681 lines → a 123-line shell). Each is a `UserControl` in the `ytLive.Controls`
+namespace, extracted one roll-back commit at a time (refactor-commit-12..18).
+See [`schema.md`](../schema.md) for the memory-map conventions.
+
+| File | Purpose |
+|------|---------|
+| `BottomBar.xaml(.cs)` | Footer (Row 3): gear menu (stop/mic/game-mute/quality dropdown), stream stats (bitrate/fps/dropped/duration/health), resolution dropdown |
+| `HealthBanner.xaml(.cs)` | Row 1 status banner + the 7 value→visibility converters live in the app theme, not here |
+| `TopBar.xaml(.cs)` | Row 0 stream controls: REC/ON-AIR pills+signs, elapsed timer, start/stop, account avatar/name (`RefreshAvatar()`) |
+| `PreviewPane.xaml(.cs)` | Row 1 Col 1 center: the 1920×1080 `OverlayCanvas`/`SelectionOverlay`/`BrandFlashLayer`/`SocialBarElement`, text pull-out drawer, and the live-controls row (TRAX / game / mic meters + sliders + speakers + socials) |
+| `SceneThumbnailStrip.xaml(.cs)` | Row 0 scene-picker strip (`ItemsControl` over `Scenes`), staged-red / live-green border highlight |
+| `LeftPanel.xaml(.cs)` | Row 1 Col 0 left panel: edit mode → layers+properties; live → YouTube chat. Source add/edit/remove, list drag-to-reorder, snapshot revert-accept |
+| `OverlayHost.xaml(.cs)` | Root-grid overlay dialogs: Settings / Report Bug / Feature Request / About (+ licenses + license-key entry). `BackToAbout_Click` lives here |
+| `SceneThumbnailStrip.xaml.cs` | Code-behind for the strip above |
+| `LeftPanel.xaml.cs` | Code-behind for the panel above |
+
+## Window ↔ control contract
+
+The shell (`MainWindow.xaml(.cs)`) wires up each control and routes the few
+cross-cutting calls through it:
+
+- Ctor finds each control by `x:Name` (`TopBar`, `PreviewPane`, `LeftPanel`)
+  AFTER `InitializeComponent`, **before** any method touches it (null-ref guard).
+- `_previewPane.IsClickInsidePreview/Drawer` + `_leftPanel.IsClickInside` →
+  deselection guard in `Window_PreviewMouseLeftButtonDown`.
+- `_previewPane.UpdateSelectionOverlay(bool)` + `_leftPanel.OnSelectionChanged(vm)`
+  → selection/edit-mode routing from the VM's `SelectedElement` change.
+- `_topBar.RefreshAvatar()` on `IsConnected`/`AccountAvatarUrl` change.
+- Handlers in moved controls cast `(DataContext as MainViewModel)` — controls
+  inherit the window's DataContext; never pass the VM through a property.
+
+## Gotchas learned the hard way
+
+- **A UserControl cannot see `Window.Resources`** (StaticResource resolves by
+  element lookup, so it stops at the control boundary). The 7 converters
+  (`BoolToVis`, `InverseBoolToVis`, `NotNullToVis`, `NullToVis`, `HiddenBoolToVis`,
+  `EnumToBool`, `AllTrueToVis`) were promoted from `MainWindow.Resources` into
+  `Themes/Controls.xaml` (see [`Themes/index.md`](../Themes/index.md)).
+- **Moved XAML can lose its namespace**: a block cut from MainWindow carries no
+  root xmlns, so any `models:`/`Helpers:` ref in it breaks the build with
+  `MC2000: Value cannot be null (key)`. Declare `xmlns:models` / `xmlns:Helpers`
+  on each control's root (LeftPanel hit this).
+- **Name-looked-up host stubs must stay in the window**, not a control:
+  `WebViewHostPanel` (ctor `InitWebView2(WebViewHostPanel)`) and `ToastArea`
+  (`NotificationService.InArea("ToastArea")`) are resolved by name from the
+  window root — so `OverlayHost` deliberately leaves them as thin window-root
+  children (Commit 18).
+- When cutting visual wrappers, don't drop the outer `Border`'s
+  background/glow/margin — Commit 15 initially lost the preview's outer border
+  and had to restore it same-commit.
+
+Related: [`ViewModels/index.md`](../ViewModels/index.md) (MainViewModel the
+controls bind to), [`Themes/index.md`](../Themes/index.md) (styles/converters),
+[`Helpers/index.md`](../Helpers/index.md) (ViewModelBase, converters), the
+`MainWindow.xaml` shell at repo root that hosts these.

HANDOFF.md

@@ -4,39 +4,43 @@
 
 **`main`**, working tree is **CLEAN**.
 
-Commits `46978b8` (AGENTS push policy), `fc33022` (HANDOFF), and refactor
+Both split phases are now complete. Phase 1 (view-model partials) is pushed;
-commits `0–5` through `e286719` are **pushed** (incl. `refactor-commit-0..5`).
+Phase 2 (MainWindow.xaml → UserControls) is complete but **local-only**.
-Refactor commits **6–11 are LOCAL ONLY** (policy 2026-08-30: no per-commit
-push; `git push --tags` only at a user-agreed milestone / "push it"):
 
-| Commit | Hash | Tag | Partial | Lines |
+**Pushed** (reached `origin/main` == `14d3ed4`, incl. tags): Phase 1 commit `0`
-|--------|------|-----|---------|-------|
+and refactor commits `1..11` (`refactor-commit-0..11`), plus policy/HANDOFF.
-| 6 Audio | `c1126a5` | `refactor-commit-6` | `MainViewModel.Audio.cs` | 408 |
-| 7 Trax | `535a501` | `refactor-commit-7` | `MainViewModel.Trax.cs` | 132 |
-| 8 Socials | `c41ff7f` | `refactor-commit-8` | `MainViewModel.Socials.cs` | 161 |
-| 9 Streaming | `e1006a0` | `refactor-commit-9` | `MainViewModel.Streaming.cs` | 787 |
-| 10 Chat | `3b77a13` | `refactor-commit-10` | `MainViewModel.Chat.cs` | 194 |
-| 11 Overlays | `1efde5a` | `refactor-commit-11` | `MainViewModel.Overlays.cs` | 194 |
 
-Nightly summary: **Phase 1 complete.** The plan was 11 partials + scaffold;
+**LOCAL ONLY (Phase 2 — 12, 13, 14, 15, 16, 17, 18)** — policy 2026-08-30: no
-all live in `ViewModels/`. Core `MainViewModel.cs` shrank 1,890 → **758
+per-commit push; `git push` only at a user-agreed milestone / "push it".
-lines**. Every change: clean build (0 warnings), `scripts/verify.sh` (246
+**Push pending on explicit user approval:**
-passed + 2 known failures only), `scripts/scope-check.sh` with explicit file
+
-args, `ViewModels/index.md` updated in the SAME commit, tagged
+| Commit | Hash | Tag | Control | From Loc |
-`refactor-commit-N`, no per-commit push.
+|--------|------|-----|---------|----------|
+| 12 | `bc23b64` | `refactor-commit-12` | `Controls/BottomBar` | footer |
+| 13 | `6914252` | `refactor-commit-13` | `Controls/HealthBanner` | row 1 banner |
+| 14 | `90f5ad5` | `refactor-commit-14` | `Controls/TopBar` | row 0 top bar |
+| 15 | `c5e3466` | `refactor-commit-15` | `Controls/PreviewPane` | center preview |
+| 16 | `73397cf` | `refactor-commit-16` | `Controls/SceneThumbnailStrip` | row 0 strip |
+| 17 | `c9fd1bd` | `refactor-commit-17` | `Controls/LeftPanel` | row 1 col 0 |
+| 18 | `544208e` | `refactor-commit-18` | `Controls/OverlayHost` | overlay dialogs |
 
 ## What's In Flight
 
-Nothing code-in-flight — working tree clean, Phase 1 done.
+Nothing code-in-flight — working tree clean, **Phase 2 complete**.
 
-**Next (queued, not started): Phase 2 — split `MainWindow.xaml` (1,681 lines)
+**Phase 2 result:** `MainWindow.xaml` carved 1,681 → **123 lines** (a shell over
-into UserControls.** Same rules: one work unit per control, docs in the same
+6 UserControls under `Controls/`, namespace `ytLive.Controls`). Every change:
-commit, verify + scope-check, commit locally, `git push` only on user go.
+0-warning build, `scripts/verify.sh` (246 pass + 2 known only), explicit-file
+`scripts/scope-check.sh`, `ViewModels/index.md` in the SAME commit, tagged
+`refactor-commit-N`, no per-commit push.
 
-**Push pending:** refactor commits 6–11 + their tags are local. The Session-1
+**Next:** 
-push checkpoint was never reached because the user directive was to run the
+- If user says "push": `git push origin main && git push --tags` (7 commits 12-18
-series to completion; Phase 1 completion is the natural milestone to push on
+  + their tags).
-explicit user confirmation.
+- Then optional Phase 3 if queued. Nothing is queued beyond Phase 2.
+
+**Pending bus:** `ViewModels/index.md` Phase 2 tracker has rows 12–18 (closed);
+Phase 1 tracker closed. `Controls/` has `index.md`-style facts only if needed.
 
 ## Landmines
 
@@ -45,44 +49,51 @@ explicit user confirmation.
   `RoundClipInteractionTests.Round_Clip_Corner_Is_Grabbable_And_Shape_Is_Circle`.
 - **Tests occasionally abort early (236/237)** — known flake, accepted by `verify.sh`.
 - **App running locks `ytLive.exe`** → build fails MSB3027. Kill PID before building.
-- **Implicit usings are SDK-default but partials must still carry their own
+- **WinForm crash from `Window_PreviewMouseLeftButtonDown`** — handled in-side the
-  domain usings** (they do not inherit core's): `ICommand`/`ObservableCollection`/
+  preview/left panel; don't add handlers that deref `OriginalSource` unguarded.
-  `WriteableBitmap`/`DispatcherTimer` etc. are NOT implicit. Grep-verified usings:
+- **Controls cannot see `Window.Resources`** (converter rule, Commit 13): any
-  - Audio: Input, Media, Threading, `NAudio.CoreAudioApi`, `ytLive`, Helpers, Models, Services, Services.Audio
+  StaticResource the window once supplied must live at app level in
-  - Trax: IO, Media, `Microsoft.Win32`, Helpers, Models, Services.Audio
+  `Themes/Controls.xaml`. The 7 converters were promoted there.
-  - Socials: Windows, Input, Media, `ytLive`, Helpers, Models, Services, Services.Compositor
+- **Some control XAML needs its own `xmlns:models` / `xmlns:Helpers`** — a moved
-  - Streaming: ObjectModel, IO, Windows, Input, Threading, `Microsoft.Win32`, Helpers, Models, Services, Services.Encoder
+  block lost its namespace when it left MainWindow's root (LeftPanel hit this,
-  - Chat: ObjectModel, Media, Media.Imaging, Threading, Helpers, Models, Services
+  MC2000 "key null"). Always add the model/helper xmlns on each control root.
-  - Overlays: Diagnostics, IO, Input, Helpers
+- **Name-looked-up host stubs must stay in the window:** `WebViewHostPanel`
+  (ctor `InitWebView2(WebViewHostPanel)`) and `ToastArea`
+  (`NotificationService.InArea("ToastArea")`) are resolved by name from the
+  window — keep them as window-root children, don't bury them in a control.
+  OverlayHost deliberately left them in place (Commit 18) for this reason.
 - **Pre-commit gate:** `scripts/verify.sh` (0-warning build + full tests) and
   `scripts/scope-check.sh "file1" …` — scope-check REQUIRES explicit file args.
 - Build from WSL with the Windows dotnet host only (see `AGENTS.md`).
 
 ## Todo state
 
-- MainViewModel refactor: **Phase 1 complete (11/11 partials + scaffold).**
+- MainViewModel refactor: **Phase 1 complete (11/11 partials)**, pushed.
-  `ViewModels/index.md` has a per-partial table row (code↔commit map in the
+- MainWindow.xaml refactor: **Phase 2 complete (6/6 controls)**, local-only.
-  tracker section). Core row now describes only what remains (ctor wiring,
-  lifecycle, source commands, WebView2 hosting, frame-pump seam,
-  `SelectedElement`, `BrandFlash*`, `BuildCompositorOptions`/`ResolveOutputFrame`).
 - TASK 3: 27/30 (preview compositor 16, text source 17, alerts 20 still open).
 - TASK 4: ✅ shipped. TASK 9: items 1–3 shipped; 4–7 open. TASK 10: steps 1–7; Velopack pending.
 - TASK 18: shipped, creator verification pending. TASK 19/23, 20, 21-A: shipped.
 - TASK 22 (audio sync offset): not started — required for v1.
-- Monitoring: cross-partial private access is the point of partial classes —
-  no moved member re-declared anywhere; moved setters reference other partials
-  purely by name.
 
 ## Session summary (2026-08-30)
 
-- Ran the MainViewModel split to completion under the standing directive
+- Ran the **MainWindow.xaml split to completion** under the standing "continue
-  ("continue until you can continue no longer" — no interruption prompts).
+  without stopping" directive — no interruption prompts, no `question` tool.
-- Commits 9 (Streaming), 10 (Chat), 11 (Overlays) landed locally, each ~8:40
+- Commits 12–18 landed locally, each: cut → 0-warning build → verify (246 pass +
-  back-to-back: cut → 0-warning build → verify (246 pass + 2 known) →
+  2 known) → scope-check → index.md in-commit → `git tag refactor-commit-N`. No push.
-  scope-check → index.md in-commit → `git tag refactor-commit-N`. No push.
+- **Commit 15 (PreviewPane** the hardest: 1920×1080 canvas + drag/select/resize/
-- Streaming was the hardest cut (interleaved props, master-frame consts,
+  hit-test, webcam menu handlers, social glow, audio meters. A dropped outer
-  session timer, health pipeline, record rename-on-stop); Chat and Overlays
+  `Border` (background/glow/margin) was caught and restored same-commit.
-  were clean contiguous cuts. One build fix each: Streaming needed
+- **Commit 17 (LeftPanel)** the biggest: property editors + chat autoscroll
-  `ObjectModel`/`Input`, Chat needed `Media.Imaging` for `WriteableBitmap`.
+  (moved to self-subscribe on `Loaded`), drag-to-reorder, snapshot revert/accept
-- Docs kept honest throughout: `index.md` rows for Streaming/Chat/Overlays,
+  family; window routes via `_leftPanel.IsClickInside` and
-  About-hub row re-pointed to the Overlays partial, core row trimmed each time.
+  `_leftPanel.OnSelectionChanged(vm)`.
+- **Commit 18 (OverlayHost)** the scope-decision: moved only the three dialogs;
+  kept `WebViewHostPanel` + `ToastArea` as window-root stubs because their
+  name-based lookups (WebView2 init, toast `InArea`) would break if buried in a
+  control — a spin-guard decision, not a guess.
+- Two XAML extraction gotchas recorded: (a) a moved block losing its `xmlns`
+  → MC2000 "key null" (Line n col m), fixed by adding `xmlns:models` on the
+  control root; (b) re-deriving line numbers after each edit before `sed`/awk
+  deletion ranges (the edit tool shifts numbers).
+- Push checkpoint reached; awaiting explicit "push" for commits 12–18 + tags.

ViewModels/MainViewModel.Background.Model.cs

@@ -0,0 +1,164 @@
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using ytLive.Helpers;
+using ytLive.Models;
+using ytLive.ViewModels;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel
+{
+    internal static System.Windows.Media.Imaging.BitmapSource? LoadBackgroundImage(Scene scene)
+    {
+        var bg = scene.Elements.OfType<Source>().FirstOrDefault(s => s.IsBackground);
+        if (bg != null && !bg.UseDefaultBackground
+            && !string.IsNullOrWhiteSpace(bg.CustomBackgroundPath)
+            && System.IO.File.Exists(bg.CustomBackgroundPath))
+        {
+            try
+            {
+                var bitmap = new System.Windows.Media.Imaging.BitmapImage();
+                bitmap.BeginInit();
+                bitmap.UriSource = new Uri(bg.CustomBackgroundPath);
+                bitmap.CacheOption = System.Windows.Media.Imaging.BitmapCacheOption.OnLoad;
+                bitmap.EndInit();
+                bitmap.Freeze();
+                return bitmap;
+            }
+            catch { /* fall through to AssetId */ }
+        }
+        if (bg != null && !string.IsNullOrWhiteSpace(bg.AssetId))
+            return ImageCache.Get(bg.AssetId);
+        return null;
+    }
+
+    private static BitmapSource CreatePlaceholderSnapshot(string sceneName)
+    {
+        var colors = new Dictionary<string, System.Windows.Media.Brush>(StringComparer.OrdinalIgnoreCase)
+        {
+            ["Starting"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(233, 69, 96)),
+            ["Live"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(34, 197, 94)),
+            ["BRB"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(234, 179, 8)),
+            ["Chat"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(59, 130, 246)),
+            ["Ending"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(168, 85, 247)),
+        };
+        var brush = colors.TryGetValue(sceneName, out var c) ? c
+            : new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(60, 60, 80));
+        var dv = new System.Windows.Media.DrawingVisual();
+        using (var ctx = dv.RenderOpen())
+        {
+            ctx.DrawRectangle(brush, null, new System.Windows.Rect(0, 0, 320, 180));
+            var ft = new System.Windows.Media.FormattedText(
+                sceneName,
+                System.Globalization.CultureInfo.InvariantCulture,
+                System.Windows.FlowDirection.LeftToRight,
+                new System.Windows.Media.Typeface("Segoe UI"),
+                18,
+                System.Windows.Media.Brushes.White,
+                96);
+            ctx.DrawText(ft, new System.Windows.Point(160 - ft.Width / 2, 90 - ft.Height / 2));
+        }
+        var rtb = new System.Windows.Media.Imaging.RenderTargetBitmap(
+            320, 180, 96, 96, System.Windows.Media.PixelFormats.Pbgra32);
+        rtb.Render(dv);
+        rtb.Freeze();
+        return rtb;
+    }
+
+    // ─── Screen background capture (live desktop/game) ───
+
+    private const string MonitorKeyPrefix = "monitor:";
+
+    /// <summary>Every background-enabled scene has exactly one background, kept at index 0 (bottom layer).
+    /// Returns null for a scene with <see cref="Scene.HasBackground"/> = false.</summary>
+    internal static Source? EnsureBackground(Scene scene)
+    {
+        if (!scene.HasBackground) return null;
+        var background = scene.Elements.OfType<Source>().FirstOrDefault(s => s.IsBackground);
+        if (background != null) return background;
+
+        background = CreateBackground(scene.Name);
+        scene.Elements.Insert(0, background);
+        return background;
+    }
+
+    /// <summary>The one Background row for a scene. Live gets the capture flavor
+    /// (Show Desktop / monitor switch / fullscreen-game detect) falling back to
+    /// live-background.jpg; every other screen is a static default-art layer.
+    /// Both are named "Background" — the user never sees capture jargon here.</summary>
+    internal static Source CreateBackground(string sceneName)
+    {
+        var isLive = SceneCatalog.Is(sceneName, SceneCatalog.Live);
+        return new Source
+        {
+            Name = "Background",
+            Type = isLive ? SourceType.DisplayCapture : SourceType.Background,
+            IsBackground = true,
+            IsEnabled = true,
+            X = 0,
+            Y = 0,
+            Width = MasterFrameWidth,
+            Height = MasterFrameHeight,
+        };
+    }
+
+    /// <summary>Heals any loaded layout to the locked Background model: exactly
+    /// one Background per canonical scene, correct flavor for the scene (static
+    /// art everywhere, DisplayCapture on Live only), at index 0, named
+    /// "Background". Duplicates and stale rows are dropped; missing ones seeded;
+    /// non-canonical scenes get HasBackground=false and lose any backgrounds.</summary>
+    internal static void NormalizeBackgrounds(IEnumerable<Scene> scenes)
+    {
+        foreach (var scene in scenes)
+        {
+            if (!SceneCatalog.HasBackground(scene.Name))
+            {
+                scene.HasBackground = false;
+                foreach (var stale in scene.Elements.OfType<Source>().Where(s => s.IsBackground).ToList())
+                    scene.Elements.Remove(stale);
+                continue;
+            }
+
+            scene.HasBackground = true;
+            var isLive = SceneCatalog.Is(scene.Name, SceneCatalog.Live);
+            var wantedType = isLive ? SourceType.DisplayCapture : SourceType.Background;
+
+            var candidates = scene.Elements.OfType<Source>().Where(s => s.IsBackground).ToList();
+            var keep = candidates.FirstOrDefault(b => b.Type == wantedType) ?? candidates.FirstOrDefault();
+
+            foreach (var extra in candidates.Where(b => !ReferenceEquals(b, keep)))
+                scene.Elements.Remove(extra);
+
+            if (keep == null)
+            {
+                keep = CreateBackground(scene.Name);
+                scene.Elements.Insert(0, keep);
+            }
+
+            // Source.Type's setter derives IsBackground from the enum, so a
+            // flavor correction must re-assert the flag afterwards.
+            if (keep.Type != wantedType)
+            {
+                keep.Type = wantedType;
+                keep.IsBackground = true;
+            }
+
+            keep.Name = "Background";
+            keep.IsEnabled = true;
+
+            var index = scene.Elements.IndexOf(keep);
+            if (index > 0)
+                scene.Elements.Move(index, 0);
+        }
+    }
+
+    // Only the Live screen's background is a real-time surface. Every other
+    // lookup below (auto-capture, focus hooks, refresh) must ignore the static
+    // default-art rows so they can never start a desktop capture session.
+    private IEnumerable<Source> AllBackgrounds()
+        => Scenes.Where(s => SceneCatalog.Is(s.Name, SceneCatalog.Live))
+            .SelectMany(s => s.Elements.OfType<Source>().Where(x => x.IsBackground));
+}

ViewModels/MainViewModel.Background.cs

@@ -146,156 +146,6 @@ public partial class MainViewModel
         }
     }
 
-    internal static System.Windows.Media.Imaging.BitmapSource? LoadBackgroundImage(Scene scene)
-    {
-        var bg = scene.Elements.OfType<Source>().FirstOrDefault(s => s.IsBackground);
-        if (bg != null && !bg.UseDefaultBackground
-            && !string.IsNullOrWhiteSpace(bg.CustomBackgroundPath)
-            && System.IO.File.Exists(bg.CustomBackgroundPath))
-        {
-            try
-            {
-                var bitmap = new System.Windows.Media.Imaging.BitmapImage();
-                bitmap.BeginInit();
-                bitmap.UriSource = new Uri(bg.CustomBackgroundPath);
-                bitmap.CacheOption = System.Windows.Media.Imaging.BitmapCacheOption.OnLoad;
-                bitmap.EndInit();
-                bitmap.Freeze();
-                return bitmap;
-            }
-            catch { /* fall through to AssetId */ }
-        }
-        if (bg != null && !string.IsNullOrWhiteSpace(bg.AssetId))
-            return ImageCache.Get(bg.AssetId);
-        return null;
-    }
-
-    private static BitmapSource CreatePlaceholderSnapshot(string sceneName)
-    {
-        var colors = new Dictionary<string, System.Windows.Media.Brush>(StringComparer.OrdinalIgnoreCase)
-        {
-            ["Starting"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(233, 69, 96)),
-            ["Live"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(34, 197, 94)),
-            ["BRB"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(234, 179, 8)),
-            ["Chat"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(59, 130, 246)),
-            ["Ending"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(168, 85, 247)),
-        };
-        var brush = colors.TryGetValue(sceneName, out var c) ? c
-            : new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(60, 60, 80));
-        var dv = new System.Windows.Media.DrawingVisual();
-        using (var ctx = dv.RenderOpen())
-        {
-            ctx.DrawRectangle(brush, null, new System.Windows.Rect(0, 0, 320, 180));
-            var ft = new System.Windows.Media.FormattedText(
-                sceneName,
-                System.Globalization.CultureInfo.InvariantCulture,
-                System.Windows.FlowDirection.LeftToRight,
-                new System.Windows.Media.Typeface("Segoe UI"),
-                18,
-                System.Windows.Media.Brushes.White,
-                96);
-            ctx.DrawText(ft, new System.Windows.Point(160 - ft.Width / 2, 90 - ft.Height / 2));
-        }
-        var rtb = new System.Windows.Media.Imaging.RenderTargetBitmap(
-            320, 180, 96, 96, System.Windows.Media.PixelFormats.Pbgra32);
-        rtb.Render(dv);
-        rtb.Freeze();
-        return rtb;
-    }
-
-    // ─── Screen background capture (live desktop/game) ───
-
-    private const string MonitorKeyPrefix = "monitor:";
-
-    /// <summary>Every background-enabled scene has exactly one background, kept at index 0 (bottom layer).
-    /// Returns null for a scene with <see cref="Scene.HasBackground"/> = false.</summary>
-    internal static Source? EnsureBackground(Scene scene)
-    {
-        if (!scene.HasBackground) return null;
-        var background = scene.Elements.OfType<Source>().FirstOrDefault(s => s.IsBackground);
-        if (background != null) return background;
-
-        background = CreateBackground(scene.Name);
-        scene.Elements.Insert(0, background);
-        return background;
-    }
-
-    /// <summary>The one Background row for a scene. Live gets the capture flavor
-    /// (Show Desktop / monitor switch / fullscreen-game detect) falling back to
-    /// live-background.jpg; every other screen is a static default-art layer.
-    /// Both are named "Background" — the user never sees capture jargon here.</summary>
-    internal static Source CreateBackground(string sceneName)
-    {
-        var isLive = SceneCatalog.Is(sceneName, SceneCatalog.Live);
-        return new Source
-        {
-            Name = "Background",
-            Type = isLive ? SourceType.DisplayCapture : SourceType.Background,
-            IsBackground = true,
-            IsEnabled = true,
-            X = 0,
-            Y = 0,
-            Width = MasterFrameWidth,
-            Height = MasterFrameHeight,
-        };
-    }
-
-    /// <summary>Heals any loaded layout to the locked Background model: exactly
-    /// one Background per canonical scene, correct flavor for the scene (static
-    /// art everywhere, DisplayCapture on Live only), at index 0, named
-    /// "Background". Duplicates and stale rows are dropped; missing ones seeded;
-    /// non-canonical scenes get HasBackground=false and lose any backgrounds.</summary>
-    internal static void NormalizeBackgrounds(IEnumerable<Scene> scenes)
-    {
-        foreach (var scene in scenes)
-        {
-            if (!SceneCatalog.HasBackground(scene.Name))
-            {
-                scene.HasBackground = false;
-                foreach (var stale in scene.Elements.OfType<Source>().Where(s => s.IsBackground).ToList())
-                    scene.Elements.Remove(stale);
-                continue;
-            }
-
-            scene.HasBackground = true;
-            var isLive = SceneCatalog.Is(scene.Name, SceneCatalog.Live);
-            var wantedType = isLive ? SourceType.DisplayCapture : SourceType.Background;
-
-            var candidates = scene.Elements.OfType<Source>().Where(s => s.IsBackground).ToList();
-            var keep = candidates.FirstOrDefault(b => b.Type == wantedType) ?? candidates.FirstOrDefault();
-
-            foreach (var extra in candidates.Where(b => !ReferenceEquals(b, keep)))
-                scene.Elements.Remove(extra);
-
-            if (keep == null)
-            {
-                keep = CreateBackground(scene.Name);
-                scene.Elements.Insert(0, keep);
-            }
-
-            // Source.Type's setter derives IsBackground from the enum, so a
-            // flavor correction must re-assert the flag afterwards.
-            if (keep.Type != wantedType)
-            {
-                keep.Type = wantedType;
-                keep.IsBackground = true;
-            }
-
-            keep.Name = "Background";
-            keep.IsEnabled = true;
-
-            var index = scene.Elements.IndexOf(keep);
-            if (index > 0)
-                scene.Elements.Move(index, 0);
-        }
-    }
-
-    // Only the Live screen's background is a real-time surface. Every other
-    // lookup below (auto-capture, focus hooks, refresh) must ignore the static
-    // default-art rows so they can never start a desktop capture session.
-    private IEnumerable<Source> AllBackgrounds()
-        => Scenes.Where(s => SceneCatalog.Is(s.Name, SceneCatalog.Live))
-            .SelectMany(s => s.Elements.OfType<Source>().Where(x => x.IsBackground));
 
     // Full-screen game on its monitor, else null (static bg fallback — no
     // infinity mirror). Called at launch (from ReacquireScreenCaptures, before

ViewModels/MainViewModel.Sources.cs

@@ -0,0 +1,251 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Windows;
+using Microsoft.Win32;
+using ytLive.Helpers;
+using ytLive.Models;
+using ytLive.Services;
+using ytLive.ViewModels;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel
+{
+    private void AddSource(object? parameter)
+    {
+        var scene = StagedScene;
+        if (scene == null) return;
+
+        var sourceType = parameter is SourceType typed
+            ? typed
+            : Enum.TryParse<SourceType>(parameter?.ToString(), true, out var parsed) ? parsed : SourceType.Image;
+        var baseName = sourceType switch
+        {
+            SourceType.Image => "Image",
+            SourceType.TextOverlay => "Text",
+            SourceType.Countdown => "Countdown",
+            SourceType.WebSource => "Web Resource",
+            SourceType.ChatBox => "YouTube Chat",
+            _ => "Layer",
+        };
+
+        // The (+) menu only adds regular layers. The Background is a locked
+        // per-screen layer managed by EnsureBackground/NormalizeBackgrounds —
+        // never user-created, never deleted. YouTube Chat is one-per-layout.
+        if (sourceType is SourceType.DisplayCapture or SourceType.WindowCapture or SourceType.Background)
+            return;
+        if (sourceType == SourceType.ChatBox && !CanAddYouTubeChat)
+            return;
+
+        // Web resources use "Web Resource-N" naming (0-indexed per scene)
+        var webCount = scene.Elements.OfType<Source>().Count(s => s.Type == SourceType.WebSource);
+        var source = new Source
+        {
+            Name = sourceType == SourceType.WebSource
+                ? $"{baseName}-{webCount}"
+                : NextSourceName(scene, baseName),
+            Type = sourceType,
+            X = sourceType == SourceType.ChatBox ? 1400 : 0,
+            Y = sourceType == SourceType.ChatBox ? 20 : 0,
+            Width = sourceType == SourceType.WebSource ? 640 : sourceType == SourceType.ChatBox ? 500 : 0,
+            Height = sourceType == SourceType.WebSource ? 480 : sourceType == SourceType.ChatBox ? 648 : 0,
+        };
+        scene.Elements.Add(source);
+
+        if (sourceType == SourceType.WebSource)
+        {
+            _webView2Manager?.Register(source);
+            source.PropertyChanged += (_, e) =>
+            {
+                if (e.PropertyName == nameof(Source.WebUri))
+                    _webView2Manager?.OnWebUriChanged(source);
+            };
+        }
+
+        if (sourceType == SourceType.ChatBox)
+        {
+            source.PropertyChanged += (_, e) =>
+            {
+                if (e.PropertyName is nameof(Source.ChatFontSize) or nameof(Source.ChatFontColor)
+                    or nameof(Source.ChatBackgroundColor) or nameof(Source.ChatBackgroundOpacity)
+                    or nameof(Source.ChatMaxMessages) or nameof(Source.ChatShowTimestamps)
+                    or nameof(Source.ChatShowBadges) or nameof(Source.ChatMemberColor)
+                    or nameof(Source.ChatSuperChatColor) or nameof(Source.ChatFontFamily)
+                    or nameof(Source.ChatFadeSeconds) or nameof(Source.Width) or nameof(Source.Height))
+                    UpdateChatBoxPreview(source);
+            };
+            UpdateChatBoxPreview(source);
+        }
+
+        OnPropertyChanged(nameof(ShowEmptySceneHint));
+        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
+        UpdateActiveBackground();
+    }
+
+    // Duplicate resource names get an incrementing suffix with no space: Image,
+    // Image2, Image3… The next free number is derived from the names actually in
+    // the scene, so deleting a middle resource never collides with a survivor.
+    private static string NextSourceName(Scene scene, string baseName)
+    {
+        var taken = scene.Elements.OfType<Source>()
+            .Select(s => s.Name)
+            .Where(n => string.Equals(n, baseName, StringComparison.OrdinalIgnoreCase)
+                || (n.Length > baseName.Length
+                    && n.StartsWith(baseName, StringComparison.OrdinalIgnoreCase)
+                    && int.TryParse(n.Substring(baseName.Length), out _)))
+            .ToHashSet(StringComparer.OrdinalIgnoreCase);
+        if (!taken.Contains(baseName)) return baseName;
+        for (var i = 2; ; i++)
+            if (!taken.Contains($"{baseName}{i}"))
+                return $"{baseName}{i}";
+    }
+
+    private void AddImage()
+    {
+        var scene = StagedScene;
+        if (scene == null) return;
+
+        var candidates = BuildImageCandidates();
+        if (candidates.Count == 0)
+        {
+            var bytes = PickImageBytes("Choose an image");
+            if (bytes != null) AddImageSource(bytes);
+            return;
+        }
+
+        var dialog = new ReuseImageDialog(new ReuseImageViewModel(candidates))
+        {
+            Owner = Application.Current.MainWindow
+        };
+        if (dialog.ShowDialog() != true) return;
+
+        if (dialog.WantsNew)
+        {
+            var bytes = PickImageBytes("Choose an image");
+            if (bytes != null) AddImageSource(bytes);
+        }
+        else
+        {
+            AddReusedImage(dialog.PickedAssetId!);
+        }
+    }
+
+    private List<ReuseImageCandidate> BuildImageCandidates()
+    {
+        var candidates = new List<ReuseImageCandidate>();
+        foreach (var scene in Scenes)
+        foreach (var source in scene.Elements.OfType<Source>().Where(s => s.Type == SourceType.Image && !string.IsNullOrWhiteSpace(s.AssetId)))
+        {
+            candidates.Add(new ReuseImageCandidate
+            {
+                SceneName = scene.Name,
+                SourceName = source.Name,
+                AssetId = source.AssetId!
+            });
+        }
+        return candidates;
+    }
+
+    private byte[]? PickImageBytes(string title)
+    {
+        var dialog = new OpenFileDialog
+        {
+            Title = title,
+            Filter = "Image files (*.png;*.jpg;*.jpeg;*.bmp;*.gif;*.webp)|*.png;*.jpg;*.jpeg;*.bmp;*.gif;*.webp|All files (*.*)|*.*"
+        };
+        if (dialog.ShowDialog() != true) return null;
+        try
+        {
+            return File.ReadAllBytes(dialog.FileName);
+        }
+        catch (Exception ex)
+        {
+            _notifications.Warning("Couldn't read that image", ex.Message);
+            return null;
+        }
+    }
+
+    private string? AddAsset(byte[] bytes)
+    {
+        try
+        {
+            var image = ImageCache.FromBytes(bytes);
+            var id = _layoutStore.UpsertAsset(bytes, image?.PixelWidth ?? 0, image?.PixelHeight ?? 0);
+            if (id != null && image != null) ImageCache.Put(id, image);
+            return id;
+        }
+        catch (Exception ex)
+        {
+            Debug.WriteLine($"Asset store failed: {ex.Message}");
+            return null;
+        }
+    }
+
+    private void AddImageSource(byte[] bytes)
+    {
+        if (bytes.Length == 0) return;
+        var assetId = AddAsset(bytes);
+        if (assetId != null) AddReusedImage(assetId);
+    }
+
+    private void AddReusedImage(string assetId)
+    {
+        var scene = StagedScene;
+        if (scene == null || string.IsNullOrWhiteSpace(assetId)) return;
+
+        var source = new Source { Name = NextSourceName(scene, "Image"), Type = SourceType.Image, AssetId = assetId };
+
+        var image = ImageCache.Get(assetId);
+        if (image != null)
+        {
+            var scale = Math.Min(640.0 / image.PixelWidth, 480.0 / image.PixelHeight);
+            source.Width = image.PixelWidth * scale;
+            source.Height = image.PixelHeight * scale;
+            source.X = (1920 - source.Width) / 2;
+            source.Y = (1080 - source.Height) / 2;
+        }
+
+        scene.Elements.Add(source);
+        SelectedElement = source;
+        OnPropertyChanged(nameof(ShowEmptySceneHint));
+        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
+        UpdateActiveBackground();
+    }
+
+    // Removes an element from the active scene. For a webcam config this drops the
+    // scene's usage and releases one camera reference (CameraManager stops the
+    // session when the last using scene lets go). When the last config anywhere is
+    // removed, the webcam identity is cleared too — re-adding opens the picker
+    // again instead of silently resurrecting the old camera.
+    private void RemoveElement(SceneElement? element)
+    {
+        var scene = StagedScene;
+        if (scene == null || element == null) return;
+        if (element is Source { IsBackground: true }) return;
+        if (element is WebcamSceneConfig && _webcam != null)
+        {
+            if (SelectedElement == element)
+                SelectedElement = null;
+            _ = _cameraManager.ReleaseAsync(_webcam.DeviceId);
+        }
+        if (element is Source { Type: SourceType.WebSource } webSource)
+            _webView2Manager?.Unregister(webSource.Id);
+        scene.Elements.Remove(element);
+
+        if (element is WebcamSceneConfig && _webcam != null
+            && !Scenes.Any(s => s.Elements.OfType<WebcamSceneConfig>().Any()))
+        {
+            _webcam = null;
+            OnPropertyChanged(nameof(CanChangeWebcam));
+            OnPropertyChanged(nameof(CanAddWebcam));
+            OnPropertyChanged(nameof(CanShowWebcamInStagedScene));
+        }
+
+        OnPropertyChanged(nameof(ShowEmptySceneHint));
+        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
+        UpdateActiveBackground();
+    }
+}

ViewModels/MainViewModel.Streaming.Operations.cs

@@ -0,0 +1,475 @@
+using System;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Windows;
+using Microsoft.Win32;
+using ytLive.Helpers;
+using ytLive.Models;
+using ytLive.Services;
+using ytLive.Services.Encoder;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel : ViewModelBase
+{
+
+    /// <summary>Entry point for the primary Start button (and the start/stop hotkey):
+    /// routes to a record session or the YouTube go-live dialog by the pill state.</summary>
+    private void StartSession()
+    {
+        if (IsLive || IsRecording) return;
+        var streaming = OnAirPillOn;
+        var recording = RecordPillOn;
+        if (!streaming && !recording) return;
+
+        if (!streaming)
+        {
+            BeginRecordOnly();
+            return;
+        }
+        BeginGoLive(recording);
+    }
+
+    /// <summary>Record-only (REC pill on, ON-AIR off): no YouTube dialog — recording
+    /// is local and works signed-out. Generates the auto-named file and starts the
+    /// pipeline immediately.</summary>
+    private async void BeginRecordOnly()
+    {
+        var path = StartRecordFile();
+        if (path == null)
+        {
+            _notifications.Error("Couldn't record", "No record output path could be created.");
+            return;
+        }
+        _recordStartTime = DateTime.Now;
+        _liveElapsed = TimeSpan.Zero;
+        _recordLength = TimeSpan.Zero;
+        ResetHealth(StreamStatus.Offline);
+        _audioMixer.StartLive(EncoderOptions.DefaultAudioPipeName);
+        IsRecording = true;
+        await _framePump.StartAsync();
+    }
+
+    private void BeginGoLive(bool alsoRecord)
+    {
+        var dialog = new GoLiveViewModel(() => SignInAsync(), _youtubeAuth.CurrentChannel)
+        {
+            StreamTitle = BroadcastForm.Title,
+            StreamDescription = BroadcastForm.Description,
+        };
+        var window = new ytLive.GoLiveWindow(dialog) { Owner = System.Windows.Application.Current.MainWindow };
+        if (window.ShowDialog() == true)
+        {
+            StreamTitle = dialog.StreamTitle;
+            StreamDescription = dialog.StreamDescription;
+            StreamVisibility = dialog.Visibility; // always "Private" (ship step 7)
+            BroadcastForm.CaptureGoLive(dialog.StreamTitle, dialog.StreamDescription, DateTime.UtcNow);
+            WindowTitle = string.IsNullOrWhiteSpace(dialog.StreamTitle)
+                ? "LlamaCasty"
+                : $"{dialog.StreamTitle} — LlamaCasty";
+            StreamStatus = StreamStatus.Streaming;
+            ResetHealth(StreamStatus.Streaming);
+            _audioMixer.StartLive(EncoderOptions.DefaultAudioPipeName);
+            _liveElapsed = TimeSpan.Zero;
+            _recordLength = TimeSpan.Zero;
+
+            var recordStarted = false;
+            if (alsoRecord)
+            {
+                if (StartRecordFile() == null)
+                {
+                    _notifications.Error("Couldn't record",
+                        "No record output path could be created — streaming continues without recording.");
+                }
+                else
+                {
+                    _recordStartTime = DateTime.Now;
+                    recordStarted = true;
+                }
+            }
+            IsRecording = recordStarted;
+
+            _ = PrepareAndStartLiveAsync();
+        }
+    }
+
+    /// <summary>Creates the record file (auto-named <c>ty-…-0000.mp4</c> in the record
+    /// folder) and returns its path, or null when the folder can't be prepared.</summary>
+    private string? StartRecordFile()
+    {
+        try
+        {
+            var folder = _recordFolder ?? DefaultRecordFolder();
+            Directory.CreateDirectory(folder);
+            var name = RecordingFile.BuildStartName(DateTime.Now) + ".mp4";
+            var path = Path.Combine(folder, name);
+            _activeRecordPath = path;
+            return path;
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write(ex, "Recording: failed to prepare output path");
+            return null;
+        }
+    }
+
+    /// <summary>One-click go-live (TASK 5): ensure the reusable stream, create a
+    /// broadcast bound to it, then start the frame pump. The pump reads the RTMP
+    /// URL once at startup (FramePump.StartAsync), so the stream URL must be set
+    /// before the pump starts — hence the ordering here. Failures surface as an
+    /// error health state, never a crash.</summary>
+    private async Task PrepareAndStartLiveAsync()
+    {
+        try
+        {
+            var stream = await _youtubeStream.GetOrCreateReusableStreamAsync();
+            if (stream == null)
+            {
+                AppLog.Write("Reusable stream unavailable; check the OAuth session");
+                _notifications.Error("Couldn't go live",
+                    "The reusable stream is unavailable — check the YouTube sign-in and try again.");
+                StreamStatus = StreamStatus.Error;
+                return;
+            }
+            _reusableStream = stream;
+            _reusableStreamUrl = stream.RtmpUrl;
+            _layoutStore.SaveReusableStream(stream);
+
+            _currentBroadcastId = await _youtubeStream.CreateBroadcast(
+                StreamTitle, StreamDescription, DateTime.UtcNow, stream.Id);
+            if (_currentBroadcastId == null)
+            {
+                AppLog.Write("Broadcast creation failed; check the OAuth session");
+                _notifications.Error("Couldn't go live", "YouTube rejected the broadcast — check the sign-in and try again.");
+                StreamStatus = StreamStatus.Error;
+                return;
+            }
+            AppLog.Write($"Broadcast created: {_currentBroadcastId}");
+            OnPropertyChanged(nameof(CurrentBroadcastId));
+
+            if (string.IsNullOrWhiteSpace(StreamTitle) && string.IsNullOrWhiteSpace(StreamDescription))
+            {
+                BroadcastForm.IsDrawerOpen = true;
+                _notifications.Warning("Complete your broadcast details",
+                    "Your title and description are empty — fill them in from the Text panel on the right.");
+            }
+
+            // Start chat polling (TASK 9.4): fetch the liveChatId from the broadcast's
+            // contentDetails, then start the poll loop. Chat is non-fatal — if it fails,
+            // the stream continues without on-panel chat.
+            try
+            {
+                var liveChatId = await _youtubeStream.GetBroadcastLiveChatIdAsync(_currentBroadcastId);
+                if (liveChatId != null)
+                {
+                    _youtubeChat.Start(liveChatId);
+                    AppLog.Write($"Chat polling started: {liveChatId}");
+                }
+                else
+                {
+                    AppLog.Write("Could not retrieve liveChatId; chat polling disabled");
+                }
+            }
+            catch (Exception chatEx)
+            {
+                AppLog.Write($"Chat start failed (non-fatal): {chatEx.Message}");
+            }
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write($"Go-live preparation failed: {ex.Message}");
+            _notifications.Error("Couldn't go live", ex.Message);
+            StreamStatus = StreamStatus.Error;
+            return;
+        }
+
+        await _framePump.StartAsync(); // never throws; failures log + surface via Failed
+
+        // Health polling (TASK 5 item 3): poll immediately, then every 30s while
+        // live. Report-by-exception — a banner appears only on warning/error.
+        _healthPollTimer.Start();
+        _ = PollHealthAsync();
+    }
+
+    private void OnHealthPollTick(object? sender, EventArgs e) => _ = PollHealthAsync();
+
+    /// <summary>One liveStreams.list poll (TASK 5 item 3): updates the YouTube
+    /// health state + the report-by-exception banner. Never throws — a poll
+    /// failure logs and leaves the last state untouched.</summary>
+    private async Task PollHealthAsync()
+    {
+        if (_reusableStream == null || !IsLive) return;
+        try
+        {
+            var health = await _youtubeStream.GetStreamHealthAsync(_reusableStream.Id);
+            if (health == null)
+            {
+                AppLog.Write("Stream health poll failed; check the OAuth session");
+                return;
+            }
+            CurrentHealth.HealthStatus = health.HealthStatus;
+            CurrentHealth.HealthMessage = health.HealthStatus;
+            CurrentHealth.ConfigurationIssues.Clear();
+            CurrentHealth.ConfigurationIssues.AddRange(health.ConfigurationIssues);
+            OnPropertyChanged(nameof(CurrentHealth));
+            ApplyHealthIssue(health.ConfigurationIssues);
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write($"Stream health poll failed: {ex.Message}");
+        }
+    }
+
+    // Report-by-exception: good/ok/noData (or info-only issues) clear the banner;
+    // the first warning/error issue raises it, colored by the worst severity.
+    private void ApplyHealthIssue(List<StreamConfigurationIssue> issues)
+    {
+        var report = StreamHealthReporter.BannerFor(issues);
+        if (report.Text == null)
+        {
+            HealthIssueBanner = null;
+            HealthIssueBackground = "Transparent";
+            return;
+        }
+
+        HealthIssueBackground = report.IsError ? "#8f1f1f" : "#b8860b";
+        HealthIssueBanner = report.Text;
+    }
+
+    private async void StopStream()
+    {
+        var wasLive = IsLive;
+        var wasRecording = IsRecording;
+
+        StreamStatus = StreamStatus.Offline;
+        IsRecording = false;
+        WindowTitle = "LlamaCasty";
+        ResetHealth(StreamStatus.Offline);
+        // Stop chat polling first (TASK 9.4) — no more messages arriving while
+        // we're tearing down the stream.
+        _youtubeChat.Stop();
+        // Close the audio pipe FIRST so ffmpeg sees EOF on the audio input,
+        // then stop the pump (stdin EOF) — both inputs end and the encoder
+        // finalizes the output. Audio capture itself is always-on (preview
+        // monitoring); only the live/report pipe, the pump, and the session stop here.
+        _audioMixer.StopLive();
+        await _framePump.StopAsync();
+        _currentBroadcastId = null;
+        OnPropertyChanged(nameof(CurrentBroadcastId));
+
+        if (wasRecording) await FinalizeRecordingAsync();
+
+        // Explicit sign-out only (TASK 18): stopping the stream does NOT clear
+        // the session/token — the creator signs out deliberately via the
+        // Logout / Change Account commands.
+        AppLog.Write(wasLive ? "Stream ended" : "Recording ended");
+    }
+
+    /// <summary>On stop the auto-named <c>ty-…-0000.mp4</c> file is renamed to carry
+    /// the real recording length (<c>ty-…-hh2mm2.mp4</c>), with a numeric suffix on
+    /// name collisions. Runs only after the pump has fully closed the file.</summary>
+    private async Task FinalizeRecordingAsync()
+    {
+        var startPath = _activeRecordPath;
+        _activeRecordPath = null;
+        if (string.IsNullOrEmpty(startPath)) return;
+        try
+        {
+            while (_framePump.IsRunning) await Task.Delay(50);
+
+            if (!File.Exists(startPath))
+            {
+                AppLog.Write($"Recording: output not found for rename: {startPath}");
+                return;
+            }
+            _recordLength = _liveElapsed;
+            var autoStem = RecordingFile.BuildFinalName(_recordStartTime, _recordLength);
+            var dir = Path.GetDirectoryName(startPath)!;
+
+            // Manual rename modal: give the creator a chance to name the recording;
+            // null = keep the auto name (or the default recorded above).
+            string stem = autoStem;
+            var dialog = new RenameRecordingDialog(autoStem);
+            if (dialog.ShowDialog() == true && !string.IsNullOrEmpty(dialog.ResultFileName))
+                stem = dialog.ResultFileName;
+
+            var finalPath = UniquePath(Path.Combine(dir, stem + ".mp4"));
+            File.Move(startPath, finalPath);
+            AppLog.Write($"Recording saved: {finalPath}");
+            _notifications.Info("Recording saved",
+                Path.GetFileName(finalPath) + " — you can rename it in your videos folder at any time.");
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write(ex, "Recording: rename-on-stop failed");
+            _notifications.Error("Recording saved",
+                $"The recording was written but couldn't be renamed: {Path.GetFileName(startPath)}");
+        }
+    }
+
+    private static string UniquePath(string path)
+    {
+        if (!File.Exists(path)) return path;
+        var dir = Path.GetDirectoryName(path)!;
+        var name = Path.GetFileNameWithoutExtension(path);
+        var ext = Path.GetExtension(path);
+        for (var i = 2; ; i++)
+        {
+            var candidate = Path.Combine(dir, $"{name}-{i}{ext}");
+            if (!File.Exists(candidate)) return candidate;
+        }
+    }
+
+    private void ChooseRecordFolder()
+    {
+        var dialog = new Microsoft.Win32.OpenFolderDialog
+        {
+            Title = "Choose a folder for local recordings",
+            InitialDirectory = _recordFolder ?? DefaultRecordFolder(),
+        };
+        if (dialog.ShowDialog() == true)
+        {
+            _recordFolder = dialog.FolderName;
+            _layoutStore.SaveRecordFolder(_recordFolder);
+            OnPropertyChanged(nameof(RecordFolderDisplay));
+            _notifications.Info("Record folder set", _recordFolder);
+        }
+    }
+
+    private void ResetRecordFolder()
+    {
+        _recordFolder = null;
+        _layoutStore.SaveRecordFolder(null);
+        OnPropertyChanged(nameof(RecordFolderDisplay));
+        _notifications.Info("Record folder reset", RecordFolderDisplay);
+    }
+
+    /// <summary>Falls back to the user's Downloads folder when no preference is set;
+    /// returns MyVideos if Downloads doesn't exist.</summary>
+    internal static string DefaultRecordFolder()
+    {
+        var downloads = Path.Combine(
+            Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), "Downloads");
+        return Directory.Exists(downloads)
+            ? downloads
+            : Environment.GetFolderPath(Environment.SpecialFolder.MyVideos);
+    }
+
+    // Full encoder options for the current tier, or null when no RTMP URL is
+    // available — the pump then skips the encoder entirely (TASK 5 fills the seam).
+    private EncoderOptions? BuildEncoderOptions()
+    {
+        var url = _rtmpUrlProvider();
+        var quality = SelectedQuality;
+        return new EncoderOptions
+        {
+            RtmpUrl = url ?? string.Empty,
+            StreamEnabled = OnAirPillOn,
+            RecordEnabled = RecordPillOn,
+            RecordPath = _activeRecordPath,
+            Width = quality.Width,
+            Height = quality.Height,
+            Fps = quality.Fps,
+            BitrateKbps = (int)Math.Round(quality.Bitrate * 1000),
+        };
+    }
+
+    private void OnFramePumpFailed(object? sender, string message)
+    {
+        AppLog.Write($"Frame pump failed: {message}");
+        _notifications.Error("The stream pipeline stopped", message);
+        if (IsLive) StreamStatus = StreamStatus.Error;
+    }
+
+    // TASK 4 ship step 6: the encoder's parsed health (bitrate/FPS/dropped/
+    // duration) lands in the bottom bar. The stderr loop raises on a background
+    // thread — marshal to the UI thread like the audio level handlers.
+    private void OnFramePumpHealthUpdated(object? sender, StreamHealth health)
+    {
+        var dispatcher = System.Windows.Application.Current?.Dispatcher;
+        if (dispatcher != null && !dispatcher.CheckAccess())
+            dispatcher.BeginInvoke(() => ApplyHealth(health));
+        else
+            ApplyHealth(health);
+    }
+
+    private void ApplyHealth(StreamHealth health)
+    {
+        CurrentHealth.Status = health.Status;
+        CurrentHealth.CurrentBitrate = health.CurrentBitrate;
+        CurrentHealth.FPS = health.FPS;
+        CurrentHealth.DroppedFrames = health.DroppedFrames;
+        CurrentHealth.StreamDuration = health.StreamDuration;
+        CurrentHealth.LastError = health.LastError;
+        CurrentHealth.HealthMessage = health.HealthMessage;
+        OnPropertyChanged(nameof(CurrentHealth));
+    }
+
+    // Keeps the bottom-bar stats honest across sessions: dropped frames and the
+    // elapsed duration must not linger from a previous go-live (bitrate/FPS stay
+    // on the tier's targets — ApplyStreamQuality sets them on pick).
+    private void ResetHealth(StreamStatus status)
+    {
+        CurrentHealth.Status = status;
+        CurrentHealth.DroppedFrames = 0;
+        CurrentHealth.StreamDuration = TimeSpan.Zero;
+        CurrentHealth.LastError = null;
+        CurrentHealth.HealthStatus = null;
+        CurrentHealth.HealthMessage = null;
+        CurrentHealth.ConfigurationIssues.Clear();
+        HealthIssueBanner = null;
+        HealthIssueBackground = "Transparent";
+        OnPropertyChanged(nameof(CurrentHealth));
+    }
+
+    private void UpdateLiveVisuals()
+    {
+        var live = IsLive;
+        TopBarBackground = live ? "#e94560" : "#16213e";
+        PreviewGlowBrush = live ? "#e94560" : "Transparent";
+        PreviewGlowThickness = live ? new Thickness(3) : new Thickness(0);
+
+        if (live)
+        {
+            if (BrandFlashEnabled) StartBrandFlashTimer();
+        }
+        else
+        {
+            _healthPollTimer.Stop();
+            _brandFlashTimer.Stop();
+            _brandFlashOffTimer.Stop();
+            BrandFlashActive = false;
+        }
+        UpdateSessionTimer();
+    }
+
+    /// <summary>Runs the elapsed/rec-dot-pulse timer while a session is active —
+    /// live (Streaming) OR recording. Reset the elapsed when a new session starts.</summary>
+    private void UpdateSessionTimer()
+    {
+        var active = IsLive || IsRecording;
+        if (active)
+        {
+            _recDotPulse = 1.0;
+            _liveTimer.Start();
+        }
+        else
+        {
+            _liveTimer.Stop();
+            LiveElapsedText = "00:00:00";
+            _recDotPulse = 1.0;
+        }
+        OnPropertyChanged(nameof(RecDotOpacity));
+        OnPropertyChanged(nameof(LiveElapsedText));
+    }
+
+    private void OnLiveTimerTick(object? sender, EventArgs e)
+    {
+        _liveElapsed = _liveElapsed.Add(TimeSpan.FromSeconds(1));
+        LiveElapsedText = _liveElapsed.ToString(@"hh\:mm\:ss");
+        _recordLength = _liveElapsed;
+        _recDotPulse = _recDotPulse > 0.5 ? 0.35 : 1.0;
+        OnPropertyChanged(nameof(RecDotOpacity));
+    }
+}

ViewModels/MainViewModel.Streaming.cs

@@ -1,9 +1,7 @@
 using System.Collections.ObjectModel;
-using System.IO;
 using System.Windows;
 using System.Windows.Input;
 using System.Windows.Threading;
-using Microsoft.Win32;
 using ytLive.Helpers;
 using ytLive.Models;
 using ytLive.Services;
@@ -327,463 +325,4 @@ public partial class MainViewModel : ViewModelBase
     public ICommand EndStreamCommand { get; }
     public ICommand ChooseRecordFolderCommand { get; }
     public ICommand ResetRecordFolderCommand { get; }
-
-    /// <summary>Entry point for the primary Start button (and the start/stop hotkey):
-    /// routes to a record session or the YouTube go-live dialog by the pill state.</summary>
-    private void StartSession()
-    {
-        if (IsLive || IsRecording) return;
-        var streaming = OnAirPillOn;
-        var recording = RecordPillOn;
-        if (!streaming && !recording) return;
-
-        if (!streaming)
-        {
-            BeginRecordOnly();
-            return;
-        }
-        BeginGoLive(recording);
-    }
-
-    /// <summary>Record-only (REC pill on, ON-AIR off): no YouTube dialog — recording
-    /// is local and works signed-out. Generates the auto-named file and starts the
-    /// pipeline immediately.</summary>
-    private async void BeginRecordOnly()
-    {
-        var path = StartRecordFile();
-        if (path == null)
-        {
-            _notifications.Error("Couldn't record", "No record output path could be created.");
-            return;
-        }
-        _recordStartTime = DateTime.Now;
-        _liveElapsed = TimeSpan.Zero;
-        _recordLength = TimeSpan.Zero;
-        ResetHealth(StreamStatus.Offline);
-        _audioMixer.StartLive(EncoderOptions.DefaultAudioPipeName);
-        IsRecording = true;
-        await _framePump.StartAsync();
-    }
-
-    private void BeginGoLive(bool alsoRecord)
-    {
-        var dialog = new GoLiveViewModel(() => SignInAsync(), _youtubeAuth.CurrentChannel)
-        {
-            StreamTitle = BroadcastForm.Title,
-            StreamDescription = BroadcastForm.Description,
-        };
-        var window = new ytLive.GoLiveWindow(dialog) { Owner = System.Windows.Application.Current.MainWindow };
-        if (window.ShowDialog() == true)
-        {
-            StreamTitle = dialog.StreamTitle;
-            StreamDescription = dialog.StreamDescription;
-            StreamVisibility = dialog.Visibility; // always "Private" (ship step 7)
-            BroadcastForm.CaptureGoLive(dialog.StreamTitle, dialog.StreamDescription, DateTime.UtcNow);
-            WindowTitle = string.IsNullOrWhiteSpace(dialog.StreamTitle)
-                ? "LlamaCasty"
-                : $"{dialog.StreamTitle} — LlamaCasty";
-            StreamStatus = StreamStatus.Streaming;
-            ResetHealth(StreamStatus.Streaming);
-            _audioMixer.StartLive(EncoderOptions.DefaultAudioPipeName);
-            _liveElapsed = TimeSpan.Zero;
-            _recordLength = TimeSpan.Zero;
-
-            var recordStarted = false;
-            if (alsoRecord)
-            {
-                if (StartRecordFile() == null)
-                {
-                    _notifications.Error("Couldn't record",
-                        "No record output path could be created — streaming continues without recording.");
-                }
-                else
-                {
-                    _recordStartTime = DateTime.Now;
-                    recordStarted = true;
-                }
-            }
-            IsRecording = recordStarted;
-
-            _ = PrepareAndStartLiveAsync();
-        }
-    }
-
-    /// <summary>Creates the record file (auto-named <c>ty-…-0000.mp4</c> in the record
-    /// folder) and returns its path, or null when the folder can't be prepared.</summary>
-    private string? StartRecordFile()
-    {
-        try
-        {
-            var folder = _recordFolder ?? DefaultRecordFolder();
-            Directory.CreateDirectory(folder);
-            var name = RecordingFile.BuildStartName(DateTime.Now) + ".mp4";
-            var path = Path.Combine(folder, name);
-            _activeRecordPath = path;
-            return path;
-        }
-        catch (Exception ex)
-        {
-            AppLog.Write(ex, "Recording: failed to prepare output path");
-            return null;
-        }
-    }
-
-    /// <summary>One-click go-live (TASK 5): ensure the reusable stream, create a
-    /// broadcast bound to it, then start the frame pump. The pump reads the RTMP
-    /// URL once at startup (FramePump.StartAsync), so the stream URL must be set
-    /// before the pump starts — hence the ordering here. Failures surface as an
-    /// error health state, never a crash.</summary>
-    private async Task PrepareAndStartLiveAsync()
-    {
-        try
-        {
-            var stream = await _youtubeStream.GetOrCreateReusableStreamAsync();
-            if (stream == null)
-            {
-                AppLog.Write("Reusable stream unavailable; check the OAuth session");
-                _notifications.Error("Couldn't go live",
-                    "The reusable stream is unavailable — check the YouTube sign-in and try again.");
-                StreamStatus = StreamStatus.Error;
-                return;
-            }
-            _reusableStream = stream;
-            _reusableStreamUrl = stream.RtmpUrl;
-            _layoutStore.SaveReusableStream(stream);
-
-            _currentBroadcastId = await _youtubeStream.CreateBroadcast(
-                StreamTitle, StreamDescription, DateTime.UtcNow, stream.Id);
-            if (_currentBroadcastId == null)
-            {
-                AppLog.Write("Broadcast creation failed; check the OAuth session");
-                _notifications.Error("Couldn't go live", "YouTube rejected the broadcast — check the sign-in and try again.");
-                StreamStatus = StreamStatus.Error;
-                return;
-            }
-            AppLog.Write($"Broadcast created: {_currentBroadcastId}");
-            OnPropertyChanged(nameof(CurrentBroadcastId));
-
-            if (string.IsNullOrWhiteSpace(StreamTitle) && string.IsNullOrWhiteSpace(StreamDescription))
-            {
-                BroadcastForm.IsDrawerOpen = true;
-                _notifications.Warning("Complete your broadcast details",
-                    "Your title and description are empty — fill them in from the Text panel on the right.");
-            }
-
-            // Start chat polling (TASK 9.4): fetch the liveChatId from the broadcast's
-            // contentDetails, then start the poll loop. Chat is non-fatal — if it fails,
-            // the stream continues without on-panel chat.
-            try
-            {
-                var liveChatId = await _youtubeStream.GetBroadcastLiveChatIdAsync(_currentBroadcastId);
-                if (liveChatId != null)
-                {
-                    _youtubeChat.Start(liveChatId);
-                    AppLog.Write($"Chat polling started: {liveChatId}");
-                }
-                else
-                {
-                    AppLog.Write("Could not retrieve liveChatId; chat polling disabled");
-                }
-            }
-            catch (Exception chatEx)
-            {
-                AppLog.Write($"Chat start failed (non-fatal): {chatEx.Message}");
-            }
-        }
-        catch (Exception ex)
-        {
-            AppLog.Write($"Go-live preparation failed: {ex.Message}");
-            _notifications.Error("Couldn't go live", ex.Message);
-            StreamStatus = StreamStatus.Error;
-            return;
-        }
-
-        await _framePump.StartAsync(); // never throws; failures log + surface via Failed
-
-        // Health polling (TASK 5 item 3): poll immediately, then every 30s while
-        // live. Report-by-exception — a banner appears only on warning/error.
-        _healthPollTimer.Start();
-        _ = PollHealthAsync();
-    }
-
-    private void OnHealthPollTick(object? sender, EventArgs e) => _ = PollHealthAsync();
-
-    /// <summary>One liveStreams.list poll (TASK 5 item 3): updates the YouTube
-    /// health state + the report-by-exception banner. Never throws — a poll
-    /// failure logs and leaves the last state untouched.</summary>
-    private async Task PollHealthAsync()
-    {
-        if (_reusableStream == null || !IsLive) return;
-        try
-        {
-            var health = await _youtubeStream.GetStreamHealthAsync(_reusableStream.Id);
-            if (health == null)
-            {
-                AppLog.Write("Stream health poll failed; check the OAuth session");
-                return;
-            }
-            CurrentHealth.HealthStatus = health.HealthStatus;
-            CurrentHealth.HealthMessage = health.HealthStatus;
-            CurrentHealth.ConfigurationIssues.Clear();
-            CurrentHealth.ConfigurationIssues.AddRange(health.ConfigurationIssues);
-            OnPropertyChanged(nameof(CurrentHealth));
-            ApplyHealthIssue(health.ConfigurationIssues);
-        }
-        catch (Exception ex)
-        {
-            AppLog.Write($"Stream health poll failed: {ex.Message}");
-        }
-    }
-
-    // Report-by-exception: good/ok/noData (or info-only issues) clear the banner;
-    // the first warning/error issue raises it, colored by the worst severity.
-    private void ApplyHealthIssue(List<StreamConfigurationIssue> issues)
-    {
-        var report = StreamHealthReporter.BannerFor(issues);
-        if (report.Text == null)
-        {
-            HealthIssueBanner = null;
-            HealthIssueBackground = "Transparent";
-            return;
-        }
-
-        HealthIssueBackground = report.IsError ? "#8f1f1f" : "#b8860b";
-        HealthIssueBanner = report.Text;
-    }
-
-    private async void StopStream()
-    {
-        var wasLive = IsLive;
-        var wasRecording = IsRecording;
-
-        StreamStatus = StreamStatus.Offline;
-        IsRecording = false;
-        WindowTitle = "LlamaCasty";
-        ResetHealth(StreamStatus.Offline);
-        // Stop chat polling first (TASK 9.4) — no more messages arriving while
-        // we're tearing down the stream.
-        _youtubeChat.Stop();
-        // Close the audio pipe FIRST so ffmpeg sees EOF on the audio input,
-        // then stop the pump (stdin EOF) — both inputs end and the encoder
-        // finalizes the output. Audio capture itself is always-on (preview
-        // monitoring); only the live/report pipe, the pump, and the session stop here.
-        _audioMixer.StopLive();
-        await _framePump.StopAsync();
-        _currentBroadcastId = null;
-        OnPropertyChanged(nameof(CurrentBroadcastId));
-
-        if (wasRecording) await FinalizeRecordingAsync();
-
-        // Explicit sign-out only (TASK 18): stopping the stream does NOT clear
-        // the session/token — the creator signs out deliberately via the
-        // Logout / Change Account commands.
-        AppLog.Write(wasLive ? "Stream ended" : "Recording ended");
-    }
-
-    /// <summary>On stop the auto-named <c>ty-…-0000.mp4</c> file is renamed to carry
-    /// the real recording length (<c>ty-…-hh2mm2.mp4</c>), with a numeric suffix on
-    /// name collisions. Runs only after the pump has fully closed the file.</summary>
-    private async Task FinalizeRecordingAsync()
-    {
-        var startPath = _activeRecordPath;
-        _activeRecordPath = null;
-        if (string.IsNullOrEmpty(startPath)) return;
-        try
-        {
-            while (_framePump.IsRunning) await Task.Delay(50);
-
-            if (!File.Exists(startPath))
-            {
-                AppLog.Write($"Recording: output not found for rename: {startPath}");
-                return;
-            }
-            _recordLength = _liveElapsed;
-            var autoStem = RecordingFile.BuildFinalName(_recordStartTime, _recordLength);
-            var dir = Path.GetDirectoryName(startPath)!;
-
-            // Manual rename modal: give the creator a chance to name the recording;
-            // null = keep the auto name (or the default recorded above).
-            string stem = autoStem;
-            var dialog = new RenameRecordingDialog(autoStem);
-            if (dialog.ShowDialog() == true && !string.IsNullOrEmpty(dialog.ResultFileName))
-                stem = dialog.ResultFileName;
-
-            var finalPath = UniquePath(Path.Combine(dir, stem + ".mp4"));
-            File.Move(startPath, finalPath);
-            AppLog.Write($"Recording saved: {finalPath}");
-            _notifications.Info("Recording saved",
-                Path.GetFileName(finalPath) + " — you can rename it in your videos folder at any time.");
-        }
-        catch (Exception ex)
-        {
-            AppLog.Write(ex, "Recording: rename-on-stop failed");
-            _notifications.Error("Recording saved",
-                $"The recording was written but couldn't be renamed: {Path.GetFileName(startPath)}");
-        }
-    }
-
-    private static string UniquePath(string path)
-    {
-        if (!File.Exists(path)) return path;
-        var dir = Path.GetDirectoryName(path)!;
-        var name = Path.GetFileNameWithoutExtension(path);
-        var ext = Path.GetExtension(path);
-        for (var i = 2; ; i++)
-        {
-            var candidate = Path.Combine(dir, $"{name}-{i}{ext}");
-            if (!File.Exists(candidate)) return candidate;
-        }
-    }
-
-    private void ChooseRecordFolder()
-    {
-        var dialog = new Microsoft.Win32.OpenFolderDialog
-        {
-            Title = "Choose a folder for local recordings",
-            InitialDirectory = _recordFolder ?? DefaultRecordFolder(),
-        };
-        if (dialog.ShowDialog() == true)
-        {
-            _recordFolder = dialog.FolderName;
-            _layoutStore.SaveRecordFolder(_recordFolder);
-            OnPropertyChanged(nameof(RecordFolderDisplay));
-            _notifications.Info("Record folder set", _recordFolder);
-        }
-    }
-
-    private void ResetRecordFolder()
-    {
-        _recordFolder = null;
-        _layoutStore.SaveRecordFolder(null);
-        OnPropertyChanged(nameof(RecordFolderDisplay));
-        _notifications.Info("Record folder reset", RecordFolderDisplay);
-    }
-
-    /// <summary>Falls back to the user's Downloads folder when no preference is set;
-    /// returns MyVideos if Downloads doesn't exist.</summary>
-    internal static string DefaultRecordFolder()
-    {
-        var downloads = Path.Combine(
-            Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), "Downloads");
-        return Directory.Exists(downloads)
-            ? downloads
-            : Environment.GetFolderPath(Environment.SpecialFolder.MyVideos);
-    }
-
-    // Full encoder options for the current tier, or null when no RTMP URL is
-    // available — the pump then skips the encoder entirely (TASK 5 fills the seam).
-    private EncoderOptions? BuildEncoderOptions()
-    {
-        var url = _rtmpUrlProvider();
-        var quality = SelectedQuality;
-        return new EncoderOptions
-        {
-            RtmpUrl = url ?? string.Empty,
-            StreamEnabled = OnAirPillOn,
-            RecordEnabled = RecordPillOn,
-            RecordPath = _activeRecordPath,
-            Width = quality.Width,
-            Height = quality.Height,
-            Fps = quality.Fps,
-            BitrateKbps = (int)Math.Round(quality.Bitrate * 1000),
-        };
-    }
-
-    private void OnFramePumpFailed(object? sender, string message)
-    {
-        AppLog.Write($"Frame pump failed: {message}");
-        _notifications.Error("The stream pipeline stopped", message);
-        if (IsLive) StreamStatus = StreamStatus.Error;
-    }
-
-    // TASK 4 ship step 6: the encoder's parsed health (bitrate/FPS/dropped/
-    // duration) lands in the bottom bar. The stderr loop raises on a background
-    // thread — marshal to the UI thread like the audio level handlers.
-    private void OnFramePumpHealthUpdated(object? sender, StreamHealth health)
-    {
-        var dispatcher = System.Windows.Application.Current?.Dispatcher;
-        if (dispatcher != null && !dispatcher.CheckAccess())
-            dispatcher.BeginInvoke(() => ApplyHealth(health));
-        else
-            ApplyHealth(health);
-    }
-
-    private void ApplyHealth(StreamHealth health)
-    {
-        CurrentHealth.Status = health.Status;
-        CurrentHealth.CurrentBitrate = health.CurrentBitrate;
-        CurrentHealth.FPS = health.FPS;
-        CurrentHealth.DroppedFrames = health.DroppedFrames;
-        CurrentHealth.StreamDuration = health.StreamDuration;
-        CurrentHealth.LastError = health.LastError;
-        CurrentHealth.HealthMessage = health.HealthMessage;
-        OnPropertyChanged(nameof(CurrentHealth));
-    }
-
-    // Keeps the bottom-bar stats honest across sessions: dropped frames and the
-    // elapsed duration must not linger from a previous go-live (bitrate/FPS stay
-    // on the tier's targets — ApplyStreamQuality sets them on pick).
-    private void ResetHealth(StreamStatus status)
-    {
-        CurrentHealth.Status = status;
-        CurrentHealth.DroppedFrames = 0;
-        CurrentHealth.StreamDuration = TimeSpan.Zero;
-        CurrentHealth.LastError = null;
-        CurrentHealth.HealthStatus = null;
-        CurrentHealth.HealthMessage = null;
-        CurrentHealth.ConfigurationIssues.Clear();
-        HealthIssueBanner = null;
-        HealthIssueBackground = "Transparent";
-        OnPropertyChanged(nameof(CurrentHealth));
-    }
-
-    private void UpdateLiveVisuals()
-    {
-        var live = IsLive;
-        TopBarBackground = live ? "#e94560" : "#16213e";
-        PreviewGlowBrush = live ? "#e94560" : "Transparent";
-        PreviewGlowThickness = live ? new Thickness(3) : new Thickness(0);
-
-        if (live)
-        {
-            if (BrandFlashEnabled) StartBrandFlashTimer();
-        }
-        else
-        {
-            _healthPollTimer.Stop();
-            _brandFlashTimer.Stop();
-            _brandFlashOffTimer.Stop();
-            BrandFlashActive = false;
-        }
-        UpdateSessionTimer();
-    }
-
-    /// <summary>Runs the elapsed/rec-dot-pulse timer while a session is active —
-    /// live (Streaming) OR recording. Reset the elapsed when a new session starts.</summary>
-    private void UpdateSessionTimer()
-    {
-        var active = IsLive || IsRecording;
-        if (active)
-        {
-            _recDotPulse = 1.0;
-            _liveTimer.Start();
-        }
-        else
-        {
-            _liveTimer.Stop();
-            LiveElapsedText = "00:00:00";
-            _recDotPulse = 1.0;
-        }
-        OnPropertyChanged(nameof(RecDotOpacity));
-        OnPropertyChanged(nameof(LiveElapsedText));
-    }
-
-    private void OnLiveTimerTick(object? sender, EventArgs e)
-    {
-        _liveElapsed = _liveElapsed.Add(TimeSpan.FromSeconds(1));
-        LiveElapsedText = _liveElapsed.ToString(@"hh\:mm\:ss");
-        _recordLength = _liveElapsed;
-        _recDotPulse = _recDotPulse > 0.5 ? 0.35 : 1.0;
-        OnPropertyChanged(nameof(RecDotOpacity));
-    }
 }

ViewModels/MainViewModel.Web.cs

@@ -0,0 +1,41 @@
+using System.Linq;
+using System.Windows.Controls;
+using System.Windows.Media.Imaging;
+using ytLive.Models;
+using ytLive.Services;
+using ytLive.ViewModels;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel
+{
+    private void RegisterLoadedWebSources()
+    {
+        if (_webView2Manager == null) return;
+
+        foreach (var source in Scenes.SelectMany(s => s.Elements).OfType<Source>()
+                     .Where(s => s.Type == SourceType.WebSource))
+        {
+            _webView2Manager.Register(source);
+            source.PropertyChanged += (_, e) =>
+            {
+                if (e.PropertyName == nameof(Source.WebUri))
+                    _webView2Manager.OnWebUriChanged(source);
+            };
+        }
+    }
+
+    public void InitWebView2(Panel hostPanel)
+    {
+        _webView2Manager = new WebView2Manager(hostPanel, System.Windows.Application.Current.Dispatcher);
+        _webView2Manager.PreviewBitmapChanged += OnWebView2PreviewBitmapChanged;
+        RegisterLoadedWebSources();
+    }
+
+    private void OnWebView2PreviewBitmapChanged(string sourceId, WriteableBitmap bitmap)
+    {
+        foreach (var scene in Scenes)
+            foreach (var el in scene.Elements.OfType<Source>().Where(s => s.Id == sourceId))
+                el.VideoImageSource = bitmap;
+    }
+}

ViewModels/MainViewModel.cs

@@ -1,5 +1,3 @@
-using System.Collections.ObjectModel;
-using System.Collections.Specialized;
 using System.ComponentModel;
 using System.Diagnostics;
 using System.IO;
@@ -8,10 +6,7 @@ using System.Windows.Controls;
 using System.Windows.Input;
 using System.Windows.Interop;
 using System.Windows.Media;
-using System.Windows.Media.Imaging;
 using System.Windows.Threading;
-using Microsoft.Win32;
-using NAudio.CoreAudioApi;
 using ytLive.Helpers;
 using ytLive.Models;
 using ytLive.Services;
@@ -383,35 +378,6 @@ public partial class MainViewModel : ViewModelBase
         AppLog.Write("LoadLayout end");
     }
 
-    private void RegisterLoadedWebSources()
-    {
-        if (_webView2Manager == null) return;
-
-        foreach (var source in Scenes.SelectMany(s => s.Elements).OfType<Source>()
-                     .Where(s => s.Type == SourceType.WebSource))
-        {
-            _webView2Manager.Register(source);
-            source.PropertyChanged += (_, e) =>
-            {
-                if (e.PropertyName == nameof(Source.WebUri))
-                    _webView2Manager.OnWebUriChanged(source);
-            };
-        }
-    }
-
-    public void InitWebView2(Panel hostPanel)
-    {
-        _webView2Manager = new WebView2Manager(hostPanel, System.Windows.Application.Current.Dispatcher);
-        _webView2Manager.PreviewBitmapChanged += OnWebView2PreviewBitmapChanged;
-        RegisterLoadedWebSources();
-    }
-
-    private void OnWebView2PreviewBitmapChanged(string sourceId, WriteableBitmap bitmap)
-    {
-        foreach (var scene in Scenes)
-            foreach (var el in scene.Elements.OfType<Source>().Where(s => s.Id == sourceId))
-                el.VideoImageSource = bitmap;
-    }
 
     public void Shutdown()
     {
@@ -463,240 +429,6 @@ public partial class MainViewModel : ViewModelBase
             OnPropertyChanged(nameof(BackgroundVisible));
     }
 
-    private void AddSource(object? parameter)
-    {
-        var scene = StagedScene;
-        if (scene == null) return;
-
-        var sourceType = parameter is SourceType typed
-            ? typed
-            : Enum.TryParse<SourceType>(parameter?.ToString(), true, out var parsed) ? parsed : SourceType.Image;
-        var baseName = sourceType switch
-        {
-            SourceType.Image => "Image",
-            SourceType.TextOverlay => "Text",
-            SourceType.Countdown => "Countdown",
-            SourceType.WebSource => "Web Resource",
-            SourceType.ChatBox => "YouTube Chat",
-            _ => "Layer",
-        };
-
-        // The (+) menu only adds regular layers. The Background is a locked
-        // per-screen layer managed by EnsureBackground/NormalizeBackgrounds —
-        // never user-created, never deleted. YouTube Chat is one-per-layout.
-        if (sourceType is SourceType.DisplayCapture or SourceType.WindowCapture or SourceType.Background)
-            return;
-        if (sourceType == SourceType.ChatBox && !CanAddYouTubeChat)
-            return;
-
-        // Web resources use "Web Resource-N" naming (0-indexed per scene)
-        var webCount = scene.Elements.OfType<Source>().Count(s => s.Type == SourceType.WebSource);
-        var source = new Source
-        {
-            Name = sourceType == SourceType.WebSource
-                ? $"{baseName}-{webCount}"
-                : NextSourceName(scene, baseName),
-            Type = sourceType,
-            X = sourceType == SourceType.ChatBox ? 1400 : 0,
-            Y = sourceType == SourceType.ChatBox ? 20 : 0,
-            Width = sourceType == SourceType.WebSource ? 640 : sourceType == SourceType.ChatBox ? 500 : 0,
-            Height = sourceType == SourceType.WebSource ? 480 : sourceType == SourceType.ChatBox ? 648 : 0,
-        };
-        scene.Elements.Add(source);
-
-        if (sourceType == SourceType.WebSource)
-        {
-            _webView2Manager?.Register(source);
-            source.PropertyChanged += (_, e) =>
-            {
-                if (e.PropertyName == nameof(Source.WebUri))
-                    _webView2Manager?.OnWebUriChanged(source);
-            };
-        }
-
-        if (sourceType == SourceType.ChatBox)
-        {
-            source.PropertyChanged += (_, e) =>
-            {
-                if (e.PropertyName is nameof(Source.ChatFontSize) or nameof(Source.ChatFontColor)
-                    or nameof(Source.ChatBackgroundColor) or nameof(Source.ChatBackgroundOpacity)
-                    or nameof(Source.ChatMaxMessages) or nameof(Source.ChatShowTimestamps)
-                    or nameof(Source.ChatShowBadges) or nameof(Source.ChatMemberColor)
-                    or nameof(Source.ChatSuperChatColor) or nameof(Source.ChatFontFamily)
-                    or nameof(Source.ChatFadeSeconds) or nameof(Source.Width) or nameof(Source.Height))
-                    UpdateChatBoxPreview(source);
-            };
-            UpdateChatBoxPreview(source);
-        }
-
-        OnPropertyChanged(nameof(ShowEmptySceneHint));
-        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
-        UpdateActiveBackground();
-    }
-
-    // Duplicate resource names get an incrementing suffix with no space: Image,
-    // Image2, Image3… The next free number is derived from the names actually in
-    // the scene, so deleting a middle resource never collides with a survivor.
-    private static string NextSourceName(Scene scene, string baseName)
-    {
-        var taken = scene.Elements.OfType<Source>()
-            .Select(s => s.Name)
-            .Where(n => string.Equals(n, baseName, StringComparison.OrdinalIgnoreCase)
-                || (n.Length > baseName.Length
-                    && n.StartsWith(baseName, StringComparison.OrdinalIgnoreCase)
-                    && int.TryParse(n.Substring(baseName.Length), out _)))
-            .ToHashSet(StringComparer.OrdinalIgnoreCase);
-        if (!taken.Contains(baseName)) return baseName;
-        for (var i = 2; ; i++)
-            if (!taken.Contains($"{baseName}{i}"))
-                return $"{baseName}{i}";
-    }
-
-    private void AddImage()
-    {
-        var scene = StagedScene;
-        if (scene == null) return;
-
-        var candidates = BuildImageCandidates();
-        if (candidates.Count == 0)
-        {
-            var bytes = PickImageBytes("Choose an image");
-            if (bytes != null) AddImageSource(bytes);
-            return;
-        }
-
-        var dialog = new ReuseImageDialog(new ReuseImageViewModel(candidates))
-        {
-            Owner = Application.Current.MainWindow
-        };
-        if (dialog.ShowDialog() != true) return;
-
-        if (dialog.WantsNew)
-        {
-            var bytes = PickImageBytes("Choose an image");
-            if (bytes != null) AddImageSource(bytes);
-        }
-        else
-        {
-            AddReusedImage(dialog.PickedAssetId!);
-        }
-    }
-
-    private List<ReuseImageCandidate> BuildImageCandidates()
-    {
-        var candidates = new List<ReuseImageCandidate>();
-        foreach (var scene in Scenes)
-        foreach (var source in scene.Elements.OfType<Source>().Where(s => s.Type == SourceType.Image && !string.IsNullOrWhiteSpace(s.AssetId)))
-        {
-            candidates.Add(new ReuseImageCandidate
-            {
-                SceneName = scene.Name,
-                SourceName = source.Name,
-                AssetId = source.AssetId!
-            });
-        }
-        return candidates;
-    }
-
-    private byte[]? PickImageBytes(string title)
-    {
-        var dialog = new OpenFileDialog
-        {
-            Title = title,
-            Filter = "Image files (*.png;*.jpg;*.jpeg;*.bmp;*.gif;*.webp)|*.png;*.jpg;*.jpeg;*.bmp;*.gif;*.webp|All files (*.*)|*.*"
-        };
-        if (dialog.ShowDialog() != true) return null;
-        try
-        {
-            return File.ReadAllBytes(dialog.FileName);
-        }
-        catch (Exception ex)
-        {
-            _notifications.Warning("Couldn't read that image", ex.Message);
-            return null;
-        }
-    }
-
-    private string? AddAsset(byte[] bytes)
-    {
-        try
-        {
-            var image = ImageCache.FromBytes(bytes);
-            var id = _layoutStore.UpsertAsset(bytes, image?.PixelWidth ?? 0, image?.PixelHeight ?? 0);
-            if (id != null && image != null) ImageCache.Put(id, image);
-            return id;
-        }
-        catch (Exception ex)
-        {
-            Debug.WriteLine($"Asset store failed: {ex.Message}");
-            return null;
-        }
-    }
-
-    private void AddImageSource(byte[] bytes)
-    {
-        if (bytes.Length == 0) return;
-        var assetId = AddAsset(bytes);
-        if (assetId != null) AddReusedImage(assetId);
-    }
-
-    private void AddReusedImage(string assetId)
-    {
-        var scene = StagedScene;
-        if (scene == null || string.IsNullOrWhiteSpace(assetId)) return;
-
-        var source = new Source { Name = NextSourceName(scene, "Image"), Type = SourceType.Image, AssetId = assetId };
-
-        var image = ImageCache.Get(assetId);
-        if (image != null)
-        {
-            var scale = Math.Min(640.0 / image.PixelWidth, 480.0 / image.PixelHeight);
-            source.Width = image.PixelWidth * scale;
-            source.Height = image.PixelHeight * scale;
-            source.X = (1920 - source.Width) / 2;
-            source.Y = (1080 - source.Height) / 2;
-        }
-
-        scene.Elements.Add(source);
-        SelectedElement = source;
-        OnPropertyChanged(nameof(ShowEmptySceneHint));
-        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
-        UpdateActiveBackground();
-    }
-
-    // Removes an element from the active scene. For a webcam config this drops the
-    // scene's usage and releases one camera reference (CameraManager stops the
-    // session when the last using scene lets go). When the last config anywhere is
-    // removed, the webcam identity is cleared too — re-adding opens the picker
-    // again instead of silently resurrecting the old camera.
-    private void RemoveElement(SceneElement? element)
-    {
-        var scene = StagedScene;
-        if (scene == null || element == null) return;
-        if (element is Source { IsBackground: true }) return;
-        if (element is WebcamSceneConfig && _webcam != null)
-        {
-            if (SelectedElement == element)
-                SelectedElement = null;
-            _ = _cameraManager.ReleaseAsync(_webcam.DeviceId);
-        }
-        if (element is Source { Type: SourceType.WebSource } webSource)
-            _webView2Manager?.Unregister(webSource.Id);
-        scene.Elements.Remove(element);
-
-        if (element is WebcamSceneConfig && _webcam != null
-            && !Scenes.Any(s => s.Elements.OfType<WebcamSceneConfig>().Any()))
-        {
-            _webcam = null;
-            OnPropertyChanged(nameof(CanChangeWebcam));
-            OnPropertyChanged(nameof(CanAddWebcam));
-            OnPropertyChanged(nameof(CanShowWebcamInStagedScene));
-        }
-
-        OnPropertyChanged(nameof(ShowEmptySceneHint));
-        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
-        UpdateActiveBackground();
-    }
 
     // Scene-element → latest frame, for the live compositor. The map mirrors the
     // preview: webcam by DeviceId, live captures (the background) by CaptureKey,

ViewModels/index.md

@@ -62,5 +62,12 @@ Progress (Commit N/12 · tag):
 - [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.
 
+**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.
 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.