feat: implement t-604 keyword prompt moderation

apps/moderation/signals.py

@@ -0,0 +1,18 @@
+from __future__ import annotations
+
+from django.db.models.signals import post_delete, post_save
+from django.dispatch import receiver
+
+from .models import SensitiveWord
+from .versioning import bump_sensitive_words_version
+
+
+@receiver(post_save, sender=SensitiveWord)
+@receiver(post_delete, sender=SensitiveWord)
+def invalidate_sensitive_words_cache(**kwargs) -> None:
+    bump_sensitive_words_version()
+    try:
+        from .providers.keyword import reset_keyword_matcher_cache
+    except Exception:
+        return
+    reset_keyword_matcher_cache()