feat(topbar): the action follows the armed output; Test is an explicit ask again

Unit C (creator ruling 2026-11-12).

- Local MP4: one button, "Start Recording".
- YouTube: "Private Test Stream" beside "Review & Go Live", the latter with the primary face because it
  is the default ask.
- Running: "End Live Stream" (or "End Test" for a test run, "Stop Recording" for a local one).

The behavioural change underneath: SessionStartDecision.For no longer takes `editing`. Since 2026-10-30
EDIT silently chose test-vs-real, which meant the same button did two different things depending on a
toggle three inches away. With Test as its own button that inference has no job, so For() now reads only
the armed output and ON-AIR always means the real livestream. That supersedes the 2026-10-30 ruling;
SessionStartDecisionTests is rewritten to pin the new matrix rather than the old one.

A signed-out press still starts the sign-in flow instead of sitting dead (no-dead-ends), unchanged from
before — now stated in one place, the two new commands, instead of inside a route table.

680 pass, 0 warnings. Scope justification: Assets/starting-background.jpg is outside this unit — the
creator's replacement art, still awaiting their visual check.

ViewModels/MainViewModel.TopBar.cs

@@ -35,11 +35,33 @@ public partial class MainViewModel
     /// running — a live session cannot change its output, so its switch is not offered.</summary>
     public bool ShowOutputStage => IsOutputWorld && IsOffline && !IsRecording;
 
+    /// <summary>The action the armed output offers: recording is one button, YouTube is two — the test
+    /// run and the real one are separate asks since 2026-11-12, not something inferred from EDIT.</summary>
+    public bool ShowStartRecordingAction => ShowOutputStage && RecordPillOn;
+    public bool ShowYouTubeStartActions => ShowOutputStage && OnAirPillOn;
+
+    public ICommand StartRecordingCommand { get; private set; } = null!;
+    public ICommand TestStreamCommand { get; private set; } = null!;
+    public ICommand GoLiveCommand { get; private set; } = null!;
+
     public ICommand EnterBuildWorldCommand { get; private set; } = null!;
     public ICommand EnterOutputWorldCommand { get; private set; } = null!;
 
     private void InitializeWorldCommands()
     {
+        StartRecordingCommand = new RelayCommand(_ => BeginRecordOnly(), _ => ShowStartRecordingAction);
+        // A signed-out press starts the sign-in flow instead of sitting dead (no-dead-ends rule).
+        TestStreamCommand = new RelayCommand(_ =>
+        {
+            if (!IsConnected) { _ = SignInAsync(); return; }
+            BeginTestStream();
+        }, _ => ShowYouTubeStartActions);
+        GoLiveCommand = new RelayCommand(_ =>
+        {
+            if (!IsConnected) { _ = SignInAsync(); return; }
+            StartSession();
+        }, _ => ShowYouTubeStartActions);
+
         EnterBuildWorldCommand = new RelayCommand(_ => EnterWorld(BarWorld.Build));
         EnterOutputWorldCommand = new RelayCommand(_ => EnterWorld(BarWorld.Output));
     }
@@ -54,5 +76,7 @@ public partial class MainViewModel
         OnPropertyChanged(nameof(IsOutputWorld));
         EditingActive = world == BarWorld.Build;
         OnPropertyChanged(nameof(ShowOutputStage));
+        OnPropertyChanged(nameof(ShowStartRecordingAction));
+        OnPropertyChanged(nameof(ShowYouTubeStartActions));
     }
 }