Tighten maybeIdlePause comment and add user-pause regression test

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: lifeart

frontend/app/services/studying-timer.ts

@@ -66,8 +66,8 @@ export default class StudyingTimerService extends Service {
   }
   @action
   maybeIdlePause() {
-    // Don't pause while audio is playing: exercises play audio without
-    // requiring mouse movement, and pausing here cascades into audio.stop().
+    // Pause cascades into audio.stop() via task-player.onPauseStateChanged,
+    // which would interrupt exercises whenever the user stops moving the mouse.
     if (this.audio.isPlaying) {
       return;
     }

frontend/tests/unit/services/studying-timer-test.js

@@ -11,24 +11,29 @@ module('Unit | Service | studying-timer', function (hooks) {
   });
 
   module('maybeIdlePause', function () {
+    function withAudio(owner, playing) {
+      owner.register('service:audio', class extends Service { isPlaying = playing; });
+      return owner.lookup('service:studying-timer');
+    }
+
     test('pauses when audio is not playing', function (assert) {
-      this.owner.register(
-        'service:audio',
-        class extends Service { isPlaying = false; },
-      );
-      const timer = this.owner.lookup('service:studying-timer');
+      const timer = withAudio(this.owner, false);
       timer.maybeIdlePause();
-      assert.true(timer.isPaused, 'isPaused set to true');
+      assert.true(timer.isPaused);
     });
 
     test('does not pause when audio is playing', function (assert) {
-      this.owner.register(
-        'service:audio',
-        class extends Service { isPlaying = true; },
-      );
-      const timer = this.owner.lookup('service:studying-timer');
+      const timer = withAudio(this.owner, true);
       timer.maybeIdlePause();
-      assert.false(timer.isPaused, 'isPaused stays false during playback');
+      assert.false(timer.isPaused);
+    });
+
+    test('user pause still works while audio plays', function (assert) {
+      // Regression guard: only maybeIdlePause should defer to audio state;
+      // direct pause() (timer button click) must remain unconditional.
+      const timer = withAudio(this.owner, true);
+      timer.pause();
+      assert.true(timer.isPaused);
     });
   });
 });