refactor: thread release config through lead path (#2612)

Co-authored-by: greatmengqi <chenmengqi.0376@bytedance.com>

backend/app/gateway/routers/suggestions.py

@@ -1,11 +1,13 @@
 import json
 import logging
 
-from fastapi import APIRouter, Request
+from fastapi import APIRouter, Depends, Request
 from langchain_core.messages import HumanMessage, SystemMessage
 from pydantic import BaseModel, Field
 
 from app.gateway.authz import require_permission
+from app.gateway.deps import get_config
+from deerflow.config.app_config import AppConfig
 from deerflow.models import create_chat_model
 
 logger = logging.getLogger(__name__)
@@ -100,7 +102,12 @@ def _format_conversation(messages: list[SuggestionMessage]) -> str:
     description="Generate short follow-up questions a user might ask next, based on recent conversation context.",
 )
 @require_permission("threads", "read", owner_check=True)
-async def generate_suggestions(thread_id: str, body: SuggestionsRequest, request: Request) -> SuggestionsResponse:
+async def generate_suggestions(
+    thread_id: str,
+    body: SuggestionsRequest,
+    request: Request,
+    config: AppConfig = Depends(get_config),
+) -> SuggestionsResponse:
     if not body.messages:
         return SuggestionsResponse(suggestions=[])
 
@@ -122,7 +129,7 @@ async def generate_suggestions(thread_id: str, body: SuggestionsRequest, request
     user_content = f"Conversation Context:\n{conversation}\n\nGenerate {n} follow-up questions"
 
     try:
-        model = create_chat_model(name=body.model_name, thinking_enabled=False)
+        model = create_chat_model(name=body.model_name, thinking_enabled=False, app_config=config)
         response = await model.ainvoke([SystemMessage(content=system_instruction), HumanMessage(content=user_content)], config={"run_name": "suggest_agent"})
         raw = _extract_response_text(response.content)
         suggestions = _parse_json_string_list(raw) or []