feat: align agent preview with learner topics

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

@@ -9,7 +9,7 @@ from fastapi.responses import StreamingResponse
 from openpyxl import Workbook, load_workbook
 from pydantic import BaseModel
 from pydantic import ValidationError
-from sqlalchemy import extract, func, select
+from sqlalchemy import extract, func, or_, select
 from sqlalchemy.orm import Session
 
 from app.core.database import get_db
@@ -267,11 +267,49 @@ def user_operation_detail(
             "recentTopics": _recent_topics(db, user.id),
             "recentHelpCards": [help_card_dict(item) for item in _recent_help_cards(db, user.id)],
             "recentShareDrafts": [share_draft_dict(item) for item in _recent_share_drafts(db, user.id)],
-            "recentReports": [periodic_report_dict(item) for item in PeriodicReportService.list_user_reports(db, user_id=user.id, limit=10)],
+            "recentReports": [
+                periodic_report_dict(item)
+                for item in PeriodicReportService.list_user_reports(db, user_id=user.id, limit=10)
+            ],
         }
     )
 
 
+@router.get("/user/{user_id}/topics")
+def user_topic_options(
+    user_id: int,
+    keyword: str = Query(default="", max_length=100),
+    page: int = Query(default=1, ge=1),
+    pageSize: int = Query(default=50, ge=10, le=100),
+    db: Session = Depends(get_db),
+    current_admin: Admin = Depends(get_current_admin),
+) -> dict:
+    """Lightweight topic selector data for Agent preview; no message bodies are returned."""
+    user = _get_user(db, user_id)
+    conditions = [TopicSession.user_id == user.id]
+    normalized_keyword = keyword.strip()
+    if normalized_keyword:
+        like = f"%{normalized_keyword}%"
+        conditions.append(or_(TopicSession.title.like(like), TopicSession.core_question.like(like)))
+    total = db.scalar(select(func.count(TopicSession.id)).where(*conditions)) or 0
+    rows = db.execute(
+        select(TopicSession, TopicSummary.id)
+        .join(TopicSummary, TopicSummary.topic_session_id == TopicSession.id, isouter=True)
+        .where(*conditions)
+        .order_by(TopicSession.updated_at.desc(), TopicSession.id.desc())
+        .offset((page - 1) * pageSize)
+        .limit(pageSize)
+    ).all()
+    items = [
+        {
+            **topic_dict(topic),
+            "summaryAvailable": summary_id is not None,
+        }
+        for topic, summary_id in rows
+    ]
+    return api_success(page_result(items, total=total, page=page, page_size=pageSize))
+
+
 @router.get("/user/{user_id}/reports")
 def user_reports(
     user_id: int,