Initial commit: KiraTV IPTV proxy server

Full-stack IPTV management system with Xtream Codes API compatibility,
multi-account provider fan-out, Jellyfin local library integration,
real-time dashboard, EPG support, and A/V-sync-safe stream recovery.

backend/models/notification.py

@@ -0,0 +1,16 @@
+from sqlalchemy import Column, Integer, String, DateTime, ForeignKey, UniqueConstraint, func
+from ..database import Base
+
+
+class NotificationDismissal(Base):
+    __tablename__ = "notification_dismissals"
+
+    id = Column(Integer, primary_key=True, index=True)
+    provider_id = Column(Integer, ForeignKey("provider_accounts.id", ondelete="CASCADE"), nullable=False)
+    category_id_str = Column(String(100), nullable=False)
+    category_type = Column(String(20), nullable=False)
+    dismissed_at = Column(DateTime(timezone=True), server_default=func.now())
+
+    __table_args__ = (
+        UniqueConstraint("provider_id", "category_id_str", "category_type", name="uq_dismissal"),
+    )