feat(pills): ON-AIR armable signed-out; Start face reads Sign-In while armed signed-out (Good Dog 2026-09-20 ruling, ai.md updated same commit)

ViewModels/MainViewModel.Streaming.cs

@@ -98,17 +98,17 @@ public partial class MainViewModel : ViewModelBase
         get => _onAirPillOn;
         set
         {
-            if (value && !CanToggleOnAir) return; // needs a sign-in
+            // Armable signed-out (creator ruling 2026-09-20: a greyed pill was a
+            // dead end — intent must be able to light while offline). The pill is
+            // intent, not reality; the Start face turns this into a sign-in.
             if (!SetProperty(ref _onAirPillOn, value)) return;
             if (value && _recordPillOn) RecordPillOn = false; // record-OR-live — arming ON-AIR drops REC
             OnPropertyChanged(nameof(ShowPrimaryStartButton));
             OnPropertyChanged(nameof(CanStartSession));
+            OnPropertyChanged(nameof(PrimaryStartButtonLabel));
         }
     }
 
-    /// <summary>The ON-AIR pill (and thus live streaming) needs a YouTube sign-in.</summary>
-    public bool CanToggleOnAir => IsConnected;
-
     /// <summary>Whether the session is actively recording — the REC status light
     /// turns green only when this is true (the pill is intent, this is reality).
     /// Internal setter is a test seam (same pattern as LayoutPathOverride) so the
@@ -140,6 +140,16 @@ public partial class MainViewModel : ViewModelBase
     /// <summary>Either output selected makes the button actionable.</summary>
     public bool CanStartSession => RecordPillOn || OnAirPillOn;
 
+    /// <summary>Face of the primary Start button. The idle face is reality-aware:
+    /// while the ON-AIR pill is armed signed-out it reads "Sign In" so intent-lit
+    /// intent is never a dead-end Start (— the pill is intent, the account is
+    /// reality, and a greyed face would be the dead end that failed to ship, creator
+    /// ruling 2026-09-20-02). The face flips back to "Start" the moment a session
+    /// connects; the armable signed-out pill gets to keep its intent through the
+    /// sign-in.</summary>
+    public string PrimaryStartButtonLabel =>
+        IsConnected || !OnAirPillOn ? "Start" : "Sign In";
+
     /// <summary>The End button shows while recording OR live.</summary>
     public bool ShowEndStreamButton => IsLive || IsRecording;