refactor(gateway): rename persistence models to external chat

surfsense_backend/app/gateway/pairing.py

@@ -1,4 +1,4 @@
-"""Pairing code lifecycle for gateway bindings."""
+"""Pairing code lifecycle for external chat bindings."""
 
 from __future__ import annotations
 
@@ -8,7 +8,7 @@ from datetime import UTC, datetime, timedelta
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.db import GatewayBindingState, GatewayConversationBinding
+from app.db import ExternalChatBindingState, ExternalChatBinding
 
 PAIRING_CODE_TTL = timedelta(minutes=10)
 
@@ -30,19 +30,19 @@ async def redeem_pairing_code(
     external_display_name: str | None,
     external_username: str | None,
     external_metadata: dict | None = None,
-) -> GatewayConversationBinding | None:
+) -> ExternalChatBinding | None:
     result = await session.execute(
-        select(GatewayConversationBinding).where(
-            GatewayConversationBinding.pairing_code == code,
-            GatewayConversationBinding.state == GatewayBindingState.PENDING,
-            GatewayConversationBinding.pairing_code_expires_at > datetime.now(UTC),
+        select(ExternalChatBinding).where(
+            ExternalChatBinding.pairing_code == code,
+            ExternalChatBinding.state == ExternalChatBindingState.PENDING,
+            ExternalChatBinding.pairing_code_expires_at > datetime.now(UTC),
         )
     )
     binding = result.scalars().first()
     if binding is None:
         return None
 
-    binding.state = GatewayBindingState.BOUND
+    binding.state = ExternalChatBindingState.BOUND
     binding.pairing_code = None
     binding.pairing_code_expires_at = None
     binding.external_peer_id = external_peer_id