持仓同步改为后台执行，添加进度条实时反馈

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ft-app/app/routers/admin.py

@@ -1,9 +1,12 @@
 from fastapi import APIRouter, Depends, Form, Request
-from fastapi.responses import HTMLResponse, RedirectResponse
+from fastapi.responses import HTMLResponse, RedirectResponse, JSONResponse
 from sqlalchemy.orm import Session
 from app.database import get_db
 from app.models import Product, Contract, DailyBar, PositionRanking
-from app.collector import sync_active_contracts, sync_one_contract, sync_position_rankings
+from app.collector import (
+    sync_active_contracts, sync_one_contract, sync_position_rankings,
+    start_sync_positions_background, get_sync_progress,
+)
 
 router = APIRouter(prefix="/admin", tags=["admin"])
 
@@ -147,10 +150,15 @@ def sync_single(contract_code: str):
 
 @router.post("/sync-positions")
 def sync_positions(request: Request):
-    results = sync_position_rankings()
-    total = sum(results.values())
-    print(f"[sync] Position rankings: {total} rows across {len(results)} contracts")
-    return RedirectResponse(f"/admin/?tab=sync&pos_synced={total}", status_code=303)
+    started = start_sync_positions_background()
+    if not started:
+        return JSONResponse({"error": "同步正在进行中，请等待完成"})
+    return JSONResponse({"started": True})
+
+
+@router.get("/sync-status")
+def sync_status():
+    return JSONResponse(get_sync_progress())
 
 
 @router.post("/sync/product/{product_id}")