refactor: extract recording-output concern into MainViewModel.Recording.cs — Commit F

The original premise (extract FFmpegEncoder / StreamHealthMonitor / FramePump
classes) was a no-op — those already exist as Services/Encoder/FfmpegEncoder.cs
and Services/Encoder/FramePump.cs. The honest functional seam was the local
recording-output concern, which was interleaved with live-stream orchestration:

- New MainViewModel.Recording.cs (121): StartRecordFile, FinalizeRecordingAsync,
  UniquePath, ChooseRecordFolder, ResetRecordFolder, DefaultRecordFolder + the
  recording fields (_recordFolder, RecordFolderDisplay, _activeRecordPath,
  _recordStartTime, _recordLength).
- MainViewModel.Streaming.Operations.cs 475 -> 377 (keeps live session lifecycle,
  health, visuals).
- MainViewModel.Streaming.cs 328 -> 323 (keeps pills/state/properties intact).

Same partial class — all MVVM bound-property glue untouched, no behavior change.
Build 0 warnings; 246 pass, only the 2 known failures.
Docs: ViewModels/index.md tracker updated in same commit.

HANDOFF.md

@@ -2,45 +2,50 @@
 
 ## Branch / Commit State
 
-**`main`**, working tree is **CLEAN**.
+**`main`**, working tree is **CLEAN**. `origin/main` == `1f4624c` (pushed).
 
-Both split phases are now complete. Phase 1 (view-model partials) is pushed;
-Phase 2 (MainWindow.xaml → UserControls) is complete but **local-only**.
+**Pushed** (reached `origin/main` == `1f4624c`, incl. tags): Phase 1 commit `0`
++ refactor commits `1..11`, **and Phase 2 commits `12..18`** (they were pushed
+at the Phase-2 milestone; the old "Phase 2 local-only" claim below was written
+before that push and is stale).
 
-**Pushed** (reached `origin/main` == `14d3ed4`, incl. tags): Phase 1 commit `0`
-and refactor commits `1..11` (`refactor-commit-0..11`), plus policy/HANDOFF.
+**LOCAL ONLY (Phase 3 — A, B, C, D, E) + the Controls doc commit** — policy
+2026-08-30: no per-commit push; `git push` only at a user-agreed milestone /
+"push it". **Push pending on explicit user approval:**
 
-**LOCAL ONLY (Phase 2 — 12, 13, 14, 15, 16, 17, 18)** — policy 2026-08-30: no
-per-commit push; `git push` only at a user-agreed milestone / "push it".
-**Push pending on explicit user approval:**
-
-| Commit | Hash | Tag | Control | From Loc |
-|--------|------|-----|---------|----------|
-| 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 |
+| Commit | Hash | Tag | Payload |
+|--------|------|-----|---------|
+| docs | `cb54637` | — | `Controls/index.md` (missing per-directory map) |
+| A | `6944db8` | `refactor-commit-A` | split `MainViewModel.cs` core → **495** |
+| B | `31362d1` | `refactor-commit-B` | split `MainViewModel.Streaming.cs` → **330** |
+| C | `fab2e09` | `refactor-commit-C` | split `MainViewModel.Background.cs` → **418** |
+| D | `d3271a0` | `refactor-commit-D` | trim `SocialsDialogViewModel.cs` → **334** |
+| E | `dcb3637` | `refactor-commit-E` | split `LayoutStore.cs` → 6 partials, **≤495** |
 
 ## What's In Flight
 
-Nothing code-in-flight — working tree clean, **Phase 2 complete**.
+Nothing code-in-flight — working tree clean, **Phase 3 complete**.
 
-**Phase 2 result:** `MainWindow.xaml` carved 1,681 → **123 lines** (a shell over
-6 UserControls under `Controls/`, namespace `ytLive.Controls`). Every change:
-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.
+**Phase 3 result:** every production `.cs` is now **≤ 500 lines** (checked via
+`git ls-files '*.cs'` minus tests; nothing exceeds 500). The 500-line count is a
+**hard ceiling, not the goal** — each file was split **grouped by functionality**
+so an AI can process one concern per file. Splits were **concern-driven**:
+- `MainViewModel` → `.Sources.cs`/`.Web.cs`, `Streaming.cs` + `Streaming.Operations.cs`,
+  `Background.cs` + `Background.Model.cs`; `SocialSlotViewModel.cs` (row VM).
+- `LayoutStore` (was 1402) → `Migrations.cs`/`Load.cs`/`Save.cs`/`Settings.cs`/
+  `Assets.cs` + a 47-line shell; `public partial class LayoutStore : IDisposable`.
+
+Every change: 0-warning build, `scripts/verify.sh` (246 pass + 2 known only),
+explicit-file `scripts/scope-check.sh`, `ViewModels/index.md` tracker in the
+SAME commit, tagged `refactor-commit-N`, no per-commit push.
 
 **Next:** 
-- If user says "push": `git push origin main && git push --tags` (7 commits 12-18
-  + their tags).
-- Then optional Phase 3 if queued. Nothing is queued beyond Phase 2.
+- If user says "push": `git push origin main && git push --tags` (6 commits:
+  `cb54637` + A–E, and tags `refactor-commit-A..E`).
 
-**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.
+**Pending bus:** `ViewModels/index.md` Phase 3 tracker has rows A–E (closed);
+Phase 3 marked COMPLETE. Watch-list (under limit, no action): `Controls/PreviewPane.xaml.cs`
+(464), `ViewModels/MainViewModel.Audio.cs` (408).
 
 ## Landmines
 
@@ -69,31 +74,29 @@ Phase 1 tracker closed. `Controls/` has `index.md`-style facts only if needed.
 ## Todo state
 
 - MainViewModel refactor: **Phase 1 complete (11/11 partials)**, pushed.
-- MainWindow.xaml refactor: **Phase 2 complete (6/6 controls)**, local-only.
+- MainWindow.xaml refactor: **Phase 2 complete (6/6 controls)**, pushed at `1f4624c`.
+- 500-line compliance: **Phase 3 complete (all 5 offenders ≤ 500)**, local-only A–E.
 - 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.
 
-## Session summary (2026-08-30)
+## Session summary (2026-08-31)
 
-- Ran the **MainWindow.xaml split to completion** under the standing "continue
+- Ran the **500-line Phase 3 split to completion** under the standing "continue
   without stopping" directive — no interruption prompts, no `question` tool.
-- Commits 12–18 landed locally, each: cut → 0-warning build → verify (246 pass +
-  2 known) → scope-check → index.md in-commit → `git tag refactor-commit-N`. No push.
-- **Commit 15 (PreviewPane** the hardest: 1920×1080 canvas + drag/select/resize/
-  hit-test, webcam menu handlers, social glow, audio meters. A dropped outer
-  `Border` (background/glow/margin) was caught and restored same-commit.
-- **Commit 17 (LeftPanel)** the biggest: property editors + chat autoscroll
-  (moved to self-subscribe on `Loaded`), drag-to-reorder, snapshot revert/accept
-  family; window routes via `_leftPanel.IsClickInside` and
-  `_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.
+- Commits A–E landed locally, each: cut → 0-warning build → verify (246 pass + 2
+  known) → scope-check → index.md in-commit → `git tag refactor-commit-{A..E}`.
+- **Re-structuring principle (user correction, 2026-08-31):** split by
+  **functionality**, so an AI can process one concern per file; the 500-line
+  count is a **ceiling**, NOT the target. Do not pad or reshape code to a
+  number — group by concern and only split enough to stay under the ceiling.
+- **Commit E (LayoutStore)** the biggest: 1402 → 6 concern-based partials
+  (Migrations/Load/Save/Settings/Assets/shell), default partial split.
+- **Accident caught & recovered (Commit D):** a `> ViewModels/SocialsDialogViewModel.cs`
+  write that read from the file it was simultaneously truncating left the file at
+  1 line. Fixed IMMEDIATELY via `git checkout --` and re-ran the split. **Lesson**
+  (goes in `MyMistakes.md`): never `awk … > SRC` where `awk` also reads `SRC`;
+  stage every multi-block cut into temp files first, then assemble. All later
+  LayoutStore cuts did exactly that (read original once into temp files).
+- Push checkpoint reached; awaiting explicit "push" for `cb54637` + A–E + tags.

MyMistakes.md

@@ -44,3 +44,26 @@ packages, high-quality downscale via `TransformedBitmap`. Screenshots compress
 4. Point `README.md` at the `.jpg` (not `.png`).
 
 **Result:** 3.2MB screenshot → 1400×794 → **188KB** `ytLlive-preview.jpg` in `docs/`.
+
+---
+
+## Splitting a large file into partials — NEVER `awk … > SRC` while awking SRC
+
+(2026-08-31, Commit D) Tried to split `SocialsDialogViewModel.cs` in one line:
+`{ awk '…' SRC; echo ""; awk '…2…' SRC; } > SRC`. The **first write truncated
+SRC to 1 line**, so the second `awk` read the already-truncated file → the whole
+source was lost (1 line left). Recovered with `git checkout -- SRC`, then redid
+it, but the same bug could have meant making it up from scratch.
+
+**Rule:** when a cut needs N blocks from one source into N files, never write a
+block back onto the source that the `awk`s still read. Instead:
+1. Read the source **once** at the start into temp files (`mktemp -d`, one file
+   per block), with a `$D` variable you carry forward.
+2. Verify block sizes (`wc -l`) and brace balance (`python3 -c` counting `{`/`}`)
+   before touching any real file.
+3. Then assemble each new file from `cat D/block …` — never truncating the source
+   until every read is done.
+
+`git status` can't save you here if you don't notice until the file is gone —
+`git checkout -- <path>` from the last commit is the recovery. Cheap insurance:
+restore-then-retry, do it atomically from temp files the first time.

ViewModels/MainViewModel.Recording.cs

@@ -0,0 +1,121 @@
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using System.Windows;
+using Microsoft.Win32;
+using ytLive.Helpers;
+using ytLive.Services;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel : ViewModelBase
+{
+    private string? _recordFolder;
+    public string RecordFolderDisplay => _recordFolder ?? DefaultRecordFolder();
+    private string? _activeRecordPath;
+    private DateTime _recordStartTime;
+    private TimeSpan _recordLength;
+
+    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;
+        }
+    }
+
+    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);
+    }
+
+    internal static string DefaultRecordFolder()
+    {
+        var downloads = Path.Combine(
+            Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), "Downloads");
+        return Directory.Exists(downloads)
+            ? downloads
+            : Environment.GetFolderPath(Environment.SpecialFolder.MyVideos);
+    }
+}

ViewModels/MainViewModel.Streaming.Operations.cs

@@ -96,23 +96,6 @@ public partial class MainViewModel : ViewModelBase
 
     /// <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
@@ -269,92 +252,11 @@ public partial class MainViewModel : ViewModelBase
     /// <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).

ViewModels/MainViewModel.Streaming.cs

@@ -38,14 +38,9 @@ public partial class MainViewModel : ViewModelBase
     private bool _recordPillOn;
     private bool _onAirPillOn;
     private bool _isRecording;
-    private string? _recordFolder;
 
     /// <summary>Resolved record folder — the configured choice, or Downloads (0th case).</summary>
-    public string RecordFolderDisplay => _recordFolder ?? DefaultRecordFolder();
 
-    private string? _activeRecordPath;
-    private DateTime _recordStartTime;
-    private TimeSpan _recordLength;
 
     private readonly FramePump _framePump;
 

ViewModels/index.md

@@ -70,6 +70,7 @@ commit, tag `refactor-commit-N`, no per-commit push).
 - [x] **Commit B · `refactor-commit-B`** — **Streaming** → `MainViewModel.Streaming.cs` 789 → **330** + new **`MainViewModel.Streaming.Operations.cs`** (459 lines). Moved the go-live/record/health operation bodies (`StartSession`, `BeginRecordOnly`, `BeginGoLive`, `StartRecordFile`, `PrepareAndStartLiveAsync`, `PollHealthAsync`/`OnHealthPollTick`/`ApplyHealthIssue`, `StopStream`, `FinalizeRecordingAsync`, `UniquePath`, `ChooseRecordFolder`, `ResetRecordFolder`, `DefaultRecordFolder`, `OnFramePumpFailed`, `OnFramePumpHealthUpdated`, `ApplyHealth`, `ResetHealth`, `BuildEncoderOptions`) into the Operations partial; Streaming.cs keeps state + quality/resolution tiers + session timer + command declarations. Pruned dead usings both files. Pending: Background, SocialsDialogViewModel, LayoutStore.
 - [x] **Commit C · `refactor-commit-C`** — **Background** → `MainViewModel.Background.cs` 567 → **418** + new **`MainViewModel.Background.Model.cs`** (163 lines). Moved the static scene-model helpers (`LoadBackgroundImage`, `CreatePlaceholderSnapshot`, `EnsureBackground`, `CreateBackground`, `NormalizeBackgrounds`, `AllBackgrounds`, `ResolveAutoCaptureKey`, `MonitorKeyPrefix`) into the Model partial; Background.cs keeps capture/live state + operations (`UpdateActiveBackground`, `UpdateBackgroundImage`, `RefreshSnapshotsAsync`, `ReacquireScreenCaptures`, `OnScreenPreviewBitmapChanged`, `OnFullscreenMonitorChanged`, `RefreshBackgroundAutoCapture`, `BrowseBackground`, `ClearBackgroundCaptureAsync`, `RedesignateBackgroundAsync`, `ChangeBackgroundCaptureAsync`, `SetBackgroundCapture`, `DefaultBackgroundAsset`, `HealBackgrounds`, `StampDefaultBackgroundAsset`). Pending: SocialsDialogViewModel, LayoutStore.
 - [x] **Commit D · `refactor-commit-D`** — **SocialsDialog** → `SocialsDialogViewModel.cs` 515 → **334** + new **`SocialSlotViewModel.cs`** (183 lines). Moved the `DialogEntry` record + the row-level `SocialSlotViewModel` (six-fixed-slot row VM: service/logo/lock/edit/validate state + computed `Show*` flags) into its own file; `SocialsDialogViewModel.cs` keeps the dialog VM (sign-in gate, validation orchestration, commit). `DialogEntry` stays `public` in the same namespace so both files see it. Pending: LayoutStore.
-- [x] **Commit E · `refactor-commit-E`** — **LayoutStore** → `LayoutStore.cs` 1402 split into 6 concern-based partials: **`LayoutStore.cs`** (47: shell — `Instance`, fields, ctor + `EnsureSchema`, `GetUserVersion`, `Dispose`), **`LayoutStore.Migrations.cs`** (495: all `Migrate*` + `EnsureSchema`), **`LayoutStore.Load.cs`** (221: `Load`), **`LayoutStore.Save.cs`** (339: `Save`), **`LayoutStore.Settings.cs`** (292: mic/record-folder/reusable-stream + license/transition/broadcast/hotkey/window `GetSetting`/`UpsertSetting`), **`LayoutStore.Assets.cs`** (41: `GetAssetBytes`/`UpsertAsset`). **PHASE 3 COMPLETE — no production `.cs` over 500.** Pending: session wrap-up (HANDOFF.md) + push on approval.
+- [x] **Commit E · `refactor-commit-E`** — **LayoutStore** → `LayoutStore.cs` 1402 split into 6 concern-based partials: **`LayoutStore.cs`** (47: shell — `Instance`, fields, ctor + `EnsureSchema`, `GetUserVersion`, `Dispose`), **`LayoutStore.Migrations.cs`** (495: all `Migrate*` + `EnsureSchema`), **`LayoutStore.Load.cs`** (221: `Load`), **`LayoutStore.Save.cs`** (339: `Save`), **`LayoutStore.Settings.cs`** (292: mic/record-folder/reusable-stream + license/transition/broadcast/hotkey/window `GetSetting`/`UpsertSetting`), **`LayoutStore.Assets.cs`** (41: `GetAssetBytes`/`UpsertAsset`). **PHASE 3 COMPLETE — no production `.cs` over 500.**
+- [x] **Commit F · `refactor-commit-F`** — **Recording (context/concern)** → new **`MainViewModel.Recording.cs`** (121 lines). The encoder (`Services/Encoder/FfmpegEncoder.cs`) and frame pump (`Services/Encoder/FramePump.cs`) were ALREADY extracted services — the planned "extract FFmpegEncoder/StreamHealthMonitor/FramePump" was a no-op premise. The honest functional seam was the local recording-output concern: `StartRecordFile`, `FinalizeRecordingAsync`, `UniquePath`, `ChooseRecordFolder`, `ResetRecordFolder`, `DefaultRecordFolder` + fields `_recordFolder`/`RecordFolderDisplay`/`_activeRecordPath`/`_recordStartTime`/`_recordLength` moved out of the live-stream orchestration. `MainViewModel.Streaming.Operations.cs` 475 → **377**; `MainViewModel.Streaming.cs` 328 → **323**. Same partial class, MVVM glue untouched.
 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.