feat: add tooltip for progress bar seeking

tests/test_music_player.py

@@ -113,6 +113,26 @@ class MusicPlayerQueueTest(unittest.IsolatedAsyncioTestCase):
         self.assertEqual(state.current.elapsed, 4.5)
         self.assertIs(voice_client.playing, state.current)
 
+    async def test_concurrent_seek_is_rejected(self):
+        player, _, _ = await self._queue_abc()
+        started = asyncio.Event()
+        release = asyncio.Event()
+
+        async def slow_recreate(track, loop=None, start_at=0.0):
+            started.set()
+            await release.wait()
+            return FakeTrack(track.id)
+
+        player._tracks.recreate = slow_recreate
+        first_seek = asyncio.create_task(player.seek(GUILD, 2))
+        await started.wait()
+
+        with self.assertRaisesRegex(RuntimeError, "already in progress"):
+            await player.seek(GUILD, 3)
+
+        release.set()
+        await first_seek
+
     async def test_loop_track_replays_same_index(self):
         player, _, state = await self._queue_abc()
         await player.play_next(GUILD, advance=True)