fix: 修复会话上下文记忆链路

ai_knowledge_base_v2/apps/backend/app/api/admin_settings.py

@@ -23,7 +23,7 @@ from app.services.feishu_service import FeishuKnowledgeService
 from app.services.knowledge_agent_service import KnowledgeAgentService
 from app.services.knowledge_service import KnowledgeScope
 from app.services.model_service import ModelClientService
-from app.services.rag_service import RagResult
+from app.services.rag_service import PromptService, RagResult
 from app.services.secret_service import MASKED_SECRET, SENSITIVE_CONFIG_KEYS, SecretService
 
 router = APIRouter()
@@ -151,14 +151,19 @@ async def debug_agent(
         version_overrides=payload.knowledgeVersions,
         preview_knowledge_ids=payload.knowledgeIds,
     )
+    debug_messages = [
+        {"role": "system", "content": payload.promptContent.strip()},
+        *(rag_result.messages or []),
+    ]
     rag_result = RagResult(
         question=rag_result.question,
         knowledge_scopes=rag_result.knowledge_scopes,
         chunks=rag_result.chunks,
-        prompt=f"{payload.promptContent.strip()}\n\n{rag_result.prompt}",
+        prompt=PromptService.render_messages(debug_messages),
         allow_general_knowledge=rag_result.allow_general_knowledge,
         retrieval_log_id=rag_result.retrieval_log_id,
         tool_trace=rag_result.tool_trace,
+        messages=debug_messages,
     )
     result = await ModelClientService.debug_model_async(
         model,