Fix SSE route dependency and align architecture docs

backend/app/api/models/__init__.py

@@ -1,5 +1,14 @@
-"""API数据模型"""
+"""Initialize the app.api.models package."""
 
+from .agent import (
+    AskRequest,
+    AskResponse,
+    ChatRequest,
+    ChatResponse,
+    FeedbackRequest,
+    SessionInfo,
+    TemplateListResponse,
+)
 from .document import (
     DocumentUploadRequest,
     DocumentUploadResponse,
@@ -9,8 +18,17 @@ from .document import (
     DocumentStatusResponse,
     ErrorResponse
 )
+# Keep package boundaries explicit so backend imports stay predictable.
+
 
 __all__ = [
+    "AskRequest",
+    "AskResponse",
+    "ChatRequest",
+    "ChatResponse",
+    "FeedbackRequest",
+    "SessionInfo",
+    "TemplateListResponse",
     "DocumentUploadRequest",
     "DocumentUploadResponse",
     "SearchRequest",