feat: require warning before mute + sustained toxicity escalation

Gate mutes behind a prior warning — first offense always gets a warning,
mute only fires if warned_since_reset is True. Warned flag is persisted
to DB (new Warned column on UserState) and survives restarts.

Add post-warning escalation boost to drama_score: each high-scoring
message after a warning adds +0.04 (configurable) so sustained bad
behavior ramps toward the mute threshold instead of plateauing.

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

utils/drama_tracker.py

@@ -70,7 +70,7 @@ class DramaTracker:
         user.last_analysis_time = now
         self._prune_entries(user, now)
 
-    def get_drama_score(self, user_id: int) -> float:
+    def get_drama_score(self, user_id: int, escalation_boost: float = 0.04) -> float:
         user = self.get_user(user_id)
         now = time.time()
         self._prune_entries(user, now)
@@ -86,7 +86,19 @@ class DramaTracker:
             weighted_sum += entry.toxicity_score * weight
             total_weight += weight
 
-        return weighted_sum / total_weight if total_weight > 0 else 0.0
+        base_score = weighted_sum / total_weight if total_weight > 0 else 0.0
+
+        # Escalation: if warned, each high-scoring message AFTER the warning
+        # adds a boost so sustained bad behavior ramps toward mute threshold
+        if user.warned_since_reset and user.last_warning_time > 0:
+            post_warn_high = sum(
+                1 for e in user.entries
+                if e.timestamp > user.last_warning_time and e.toxicity_score >= 0.5
+            )
+            if post_warn_high > 0:
+                base_score += escalation_boost * post_warn_high
+
+        return min(base_score, 1.0)
 
     def get_mute_threshold(self, user_id: int, base_threshold: float) -> float:
         """Lower the mute threshold if user was already warned."""
@@ -272,6 +284,8 @@ class DramaTracker:
                 user.baseline_coherence = state["baseline_coherence"]
             if "user_notes" in state and state["user_notes"]:
                 user.notes = state["user_notes"]
+            if state.get("warned"):
+                user.warned_since_reset = True
             count += 1
         return count