feat: move user aliases from config to DB with /bcs-alias command

Aliases now stored in UserState table instead of config.yaml. Adds
Aliases column (NVARCHAR 500), loads on startup, persists via flush.
New /bcs-alias slash command (view/set/clear) for managing nicknames.

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

utils/drama_tracker.py

@@ -30,6 +30,8 @@ class UserDrama:
     last_coherence_alert_time: float = 0.0
     # Per-user LLM notes
     notes: str = ""
+    # Known aliases/nicknames
+    aliases: list[str] = field(default_factory=list)
 
 
 class DramaTracker:
@@ -217,6 +219,16 @@ class DramaTracker:
     def clear_user_notes(self, user_id: int) -> None:
         self.get_user(user_id).notes = ""
 
+    def get_user_aliases(self, user_id: int) -> list[str]:
+        return self.get_user(user_id).aliases
+
+    def set_user_aliases(self, user_id: int, aliases: list[str]) -> None:
+        self.get_user(user_id).aliases = aliases
+
+    def get_all_aliases(self) -> dict[int, list[str]]:
+        """Return {user_id: [aliases]} for all users that have aliases set."""
+        return {uid: user.aliases for uid, user in self._users.items() if user.aliases}
+
     def reset_off_topic(self, user_id: int) -> None:
         user = self.get_user(user_id)
         user.off_topic_count = 0
@@ -298,6 +310,8 @@ class DramaTracker:
                     user.offense_count = 0
                     user.warned_since_reset = False
                     user.last_offense_time = 0.0
+            if state.get("aliases"):
+                user.aliases = [a.strip() for a in state["aliases"].split(",") if a.strip()]
             count += 1
         return count