test: add behavioral assertions to composer tests

Upgrade 8 composer test files from shape-only typeof checks to behavioral
assertions that invoke returned handlers and verify injected dependencies are
actually called, following the mpv-runtime-composer pattern.

src/main/runtime/composers/overlay-visibility-runtime-composer.test.ts

@@ -3,15 +3,20 @@ import test from 'node:test';
 import { composeOverlayVisibilityRuntime } from './overlay-visibility-runtime-composer';
 
 test('composeOverlayVisibilityRuntime returns overlay visibility handlers', () => {
+  const calls: string[] = [];
   const composed = composeOverlayVisibilityRuntime({
     overlayVisibilityRuntime: {
-      updateVisibleOverlayVisibility: () => {},
+      updateVisibleOverlayVisibility: () => {
+        calls.push('updateVisibleOverlayVisibility');
+      },
     },
     restorePreviousSecondarySubVisibilityMainDeps: {
       getMpvClient: () => null,
     },
     broadcastRuntimeOptionsChangedMainDeps: {
-      broadcastRuntimeOptionsChangedRuntime: () => {},
+      broadcastRuntimeOptionsChangedRuntime: () => {
+        calls.push('broadcastRuntimeOptionsChangedRuntime');
+      },
       getRuntimeOptionsState: () => [],
       broadcastToOverlayWindows: () => {},
     },
@@ -24,7 +29,9 @@ test('composeOverlayVisibilityRuntime returns overlay visibility handlers', () =
       setCurrentEnabled: () => {},
     },
     openRuntimeOptionsPaletteMainDeps: {
-      openRuntimeOptionsPaletteRuntime: () => {},
+      openRuntimeOptionsPaletteRuntime: () => {
+        calls.push('openRuntimeOptionsPaletteRuntime');
+      },
     },
   });
 
@@ -34,4 +41,16 @@ test('composeOverlayVisibilityRuntime returns overlay visibility handlers', () =
   assert.equal(typeof composed.sendToActiveOverlayWindow, 'function');
   assert.equal(typeof composed.setOverlayDebugVisualizationEnabled, 'function');
   assert.equal(typeof composed.openRuntimeOptionsPalette, 'function');
+
+  // updateVisibleOverlayVisibility passes through to the injected runtime dep
+  composed.updateVisibleOverlayVisibility();
+  assert.deepEqual(calls, ['updateVisibleOverlayVisibility']);
+
+  // openRuntimeOptionsPalette forwards to the injected runtime dep
+  composed.openRuntimeOptionsPalette();
+  assert.deepEqual(calls, ['updateVisibleOverlayVisibility', 'openRuntimeOptionsPaletteRuntime']);
+
+  // broadcastRuntimeOptionsChanged forwards to the injected runtime dep
+  composed.broadcastRuntimeOptionsChanged();
+  assert.ok(calls.includes('broadcastRuntimeOptionsChangedRuntime'));
 });