Simplify user notes trimming to keep last 10 lines

Replace character-based truncation loop with a simple line count cap.

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

utils/drama_tracker.py

@@ -192,12 +192,10 @@ class DramaTracker:
             user.notes = f"{user.notes}\n{new_line}"
         else:
             user.notes = new_line
-        # Trim oldest lines if over ~2000 chars
-        while len(user.notes) > 2000:
-            lines = user.notes.split("\n")
-            if len(lines) <= 1:
-                break
-            user.notes = "\n".join(lines[1:])
+        # Keep only the 10 most recent lines
+        lines = user.notes.split("\n")
+        if len(lines) > 10:
+            user.notes = "\n".join(lines[-10:])
 
     def clear_user_notes(self, user_id: int) -> None:
         self.get_user(user_id).notes = ""