Apply shell theme if background reveal stalls

shell/plugins/background/Background.qml

@@ -66,10 +66,12 @@ Item {
     pendingColorsRaw = Util.decodeBase64(colorsB64)
     pendingShellRaw = Util.decodeBase64(shellB64)
     pendingThemeVersion = backgroundVersion
+    pendingThemeFallbackTimer.restart()
   }
 
   function applyPendingTheme() {
     if (pendingThemeVersion !== backgroundVersion) return
+    pendingThemeFallbackTimer.stop()
     Color.loadColors(pendingColorsRaw)
     // Color.loadShell also refreshes Style so the type scale flips with the
     // background reveal instead of waiting for a separate reload path.
@@ -154,6 +156,13 @@ Item {
     onTriggered: root.refreshBackground()
   }
 
+  Timer {
+    id: pendingThemeFallbackTimer
+    interval: 300
+    repeat: false
+    onTriggered: root.applyPendingTheme()
+  }
+
   NumberAnimation {
     id: revealAnimation
     target: root

test/shell.d/background-test.sh

@@ -10,4 +10,11 @@ assert(
   /theme=\$\(omarchy-theme-switcher\); \[\[ -n \$theme \]\] && omarchy-theme-set \\"\$theme\\" >\/dev\/null 2>&1 &/.test(backgroundQml),
   'background theme switcher starts theme application asynchronously after selection'
 )
+
+assert(
+  backgroundQml.includes('pendingThemeFallbackTimer.restart()') &&
+    backgroundQml.includes('pendingThemeFallbackTimer.stop()') &&
+    backgroundQml.includes('id: pendingThemeFallbackTimer'),
+  'background theme transition applies pending colors even if image reveal stalls'
+)
 JS