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.

ytLive.Tests/SessionStartDecisionTests.cs

@@ -3,27 +3,22 @@ using ytLive.Models;
 
 namespace ytLive.Tests;
 
-/// <summary>Creator ruling (2026-10-30): the top bar's primary button is context-sensitive and the
-/// separate TEST button is gone.
+/// <summary>Which session an armed output starts, and where a press routes.
 ///
-/// <para>EDIT off + ON-AIR → the livestream message. EDIT on + ON-AIR → the test-livestream
-/// message. REC always records, because there is no test recording. The matrix is pure, so it is
-/// cheaper to pin it here than to drive a window.</para></summary>
+/// <para>Superseded 2026-11-12: the ON-AIR start no longer infers Test from EDIT. The output stage
+/// offers "Private Test Stream" and "Review & Go Live" as separate buttons, so ON-AIR always means the
+/// real livestream here. REC always records, because there is no test recording.</para></summary>
 public class SessionStartDecisionTests
 {
     [Fact]
-    public void Edit_decides_whether_the_on_air_start_is_live_or_a_test()
+    public void The_armed_output_decides_the_session_kind_and_test_is_never_inferred()
     {
-        // ON-AIR armed: EDIT decides.
-        Assert.Equal(SessionStartKind.Live, SessionStartDecision.For(recordArmed: false, onAirArmed: true, editing: false));
+        // ON-AIR armed: the real livestream, never a test.
+        Assert.Equal(SessionStartKind.Live, SessionStartDecision.For(recordArmed: false, onAirArmed: true));
         Assert.Equal("Go Live", SessionStartDecision.LabelFor(SessionStartKind.Live));
 
-        Assert.Equal(SessionStartKind.Test, SessionStartDecision.For(recordArmed: false, onAirArmed: true, editing: true));
-        Assert.Equal("Test Stream", SessionStartDecision.LabelFor(SessionStartKind.Test));
-
-        // REC armed: always a recording, whatever EDIT says (no test recording exists).
-        Assert.Equal(SessionStartKind.Record, SessionStartDecision.For(true, false, false));
-        Assert.Equal(SessionStartKind.Record, SessionStartDecision.For(true, false, true));
+        // REC armed: always a recording (no test recording exists).
+        Assert.Equal(SessionStartKind.Record, SessionStartDecision.For(true, false));
         Assert.Equal("Start Recording", SessionStartDecision.LabelFor(SessionStartKind.Record));
 
         // Signed out: an ON-AIR press (live OR test) routes to the sign-in flow, never a dead
@@ -35,6 +30,6 @@ public class SessionStartDecisionTests
         Assert.Equal(SessionStartDecision.Route.Record, SessionStartDecision.RouteFor(SessionStartKind.Record, connected: false));
 
         // Unarmed start records locally (the no-dead-ends rule).
-        Assert.Equal(SessionStartKind.Record, SessionStartDecision.For(false, false, false));
+        Assert.Equal(SessionStartKind.Record, SessionStartDecision.For(false, false));
     }
 }

ytLive.Tests/TopBarWorldTests.cs

@@ -39,6 +39,18 @@ public class TopBarWorldTests
             Assert.False(vm.RecordPillOn);
             vm.RecordPillOn = true;
             Assert.False(vm.OnAirPillOn);
+
+            // The action follows the output: one button for MP4, two for YouTube (test + real).
+            Assert.True(vm.ShowStartRecordingAction);
+            Assert.False(vm.ShowYouTubeStartActions);
+            vm.OnAirPillOn = true;
+            Assert.False(vm.ShowStartRecordingAction);
+            Assert.True(vm.ShowYouTubeStartActions);
+
+            // Neither action exists while building scenes.
+            vm.EnterBuildWorldCommand.Execute(null);
+            Assert.False(vm.ShowStartRecordingAction);
+            Assert.False(vm.ShowYouTubeStartActions);
         }
         finally
         {

ytLive.Tests/UiShellTests.cs

@@ -49,6 +49,11 @@ public class UiShellTests
         Assert.Contains("IsChecked=\"{Binding OnAirPillOn}\"", topBar);
         Assert.Contains("IsChecked=\"{Binding RecordPillOn}\"", topBar);
 
+        // 2d. The action follows the armed output, and Test is an explicit ask again.
+        Assert.Contains("Content=\"Start Recording\"", topBar);
+        Assert.Contains("Content=\"Private Test Stream\"", topBar);
+        Assert.Contains("Content=\"Review & Go Live\"", topBar);
+
         // 3. Active scene = orange; live stays red.
         Assert.Contains("IsStaged}\" Value=\"True\">\n                                        <Setter Property=\"BorderBrush\" Value=\"{StaticResource Brush.Attention}\"/>", strip);