fix: race condition in skip/seek/stop losing track state

task.cancel() triggers _play_loop's finally block asynchronously.
When cmd_skip or cmd_seek called _ensure_loop before the finally
block ran, the old task's cleanup would overwrite the new task's
state -- causing !np to report "Nothing playing" while audio
was still streaming.

Now await the cancelled task before restarting the loop, ensuring
the finally block completes first.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

plugins/music.py

@@ -537,9 +537,13 @@ async def cmd_stop(bot, message):
     task = ps.get("task")
     if task and not task.done():
         task.cancel()
+        try:
+            await task
+        except (asyncio.CancelledError, Exception):
+            pass
+    else:
         ps["current"] = None
         ps["task"] = None
-    ps["done_event"] = None
         ps["duck_vol"] = None
 
     await bot.reply(message, "Stopped")
@@ -593,14 +597,15 @@ async def cmd_skip(bot, message):
         await bot.reply(message, "Nothing playing")
         return
 
+    skipped = ps["current"]
+
     task = ps.get("task")
     if task and not task.done():
         task.cancel()
-
-    skipped = ps["current"]
-    ps["current"] = None
-    ps["task"] = None
-    ps["duck_vol"] = None
+        try:
+            await task
+        except (asyncio.CancelledError, Exception):
+            pass
 
     if ps["queue"]:
         _ensure_loop(bot)
@@ -657,13 +662,14 @@ async def cmd_seek(bot, message):
     # Re-insert current track at front of queue (local_path intact)
     ps["queue"].insert(0, track)
 
-    # Cancel the play loop
+    # Cancel the play loop and wait for cleanup
     task = ps.get("task")
     if task and not task.done():
         task.cancel()
-    ps["current"] = None
-    ps["task"] = None
-    ps["duck_vol"] = None
+        try:
+            await task
+        except (asyncio.CancelledError, Exception):
+            pass
 
     _ensure_loop(bot, seek=target)
     await bot.reply(message, f"Seeking to {_fmt_time(target)}")