Phase2: 真实热点数据接入

- trends.py新增百度/微博/知乎实时热搜API抓取，LLM为fallback
- 新增 source 字段标记数据来源
- scheduler.py新增 scheduled_fetch_trends 每日03:00定时刷新
- system.py新增 POST /api/system/trends/run 手动触发端点
- system.py modules/status 加入热点趋势模块
- index.html triggerModule 加入 trends 触发按钮

platform/backend/app/api/system.py

@@ -176,6 +176,23 @@ def trigger_metrics_sync():
     except Exception as e:
         raise HTTPException(status_code=500, detail=str(e))
 
+@router.post("/trends/run")
+def trigger_trends_refresh():
+    """手动刷新热点趋势数据"""
+    try:
+        import subprocess, sys as sys_mod
+        from pathlib import Path
+        scripts_dir = Path(__file__).parent.parent.parent.parent / "scripts"
+        result = subprocess.run(
+            [sys_mod.executable, str(scripts_dir / "trends.py")],
+            capture_output=True, text=True, timeout=120
+        )
+        if result.returncode != 0:
+            raise Exception(result.stderr[-500:])
+        return {"message": "热点趋势已刷新", "output": result.stdout.strip()}
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+
 @router.get("/automation/topics")
 def list_automation_topics(db: Session = Depends(get_db), current_user=Depends(get_current_user)):
     try:
@@ -221,6 +238,7 @@ def get_modules_status():
     today_str = date.today().isoformat()
     log_based: dict = {
         "scheduled_collect": {"name": "📡 内容采集", "log": LOGS_DIR / f"collector_{today_str}.log"},
+        "scheduled_fetch_trends": {"name": "🔥 热点趋势", "log": LOGS_DIR / f"trends_{today_str}.log"},
         "scheduled_generate": {"name": "🤖 内容创作", "log": LOGS_DIR / f"creator_{today_str}.log"},
         "scheduled_optimize": {"name": "🔍 合规审查", "log": LOGS_DIR / f"optimizer_{today_str}.log"},
         "scheduled_optimize_sources": {"name": "📡 信息源优化", "log": LOGS_DIR / f"optimizer_sources_{today_str}.log"},