feat(server): expose active_sites in /status

The frontend needs to know which sites are actually mounted this
session (debug mode mounts only target_site). /status now returns
active_sites = ctx.sites_to_watch, so the dashboard can stop counting
stale login_state values from previous sessions as online.

inbound_verify/cli/server.py

@@ -322,10 +322,19 @@ def run_compare(req: CompareRequest):
 
 @app.get("/status")
 def get_status():
-    """各站登录态 + 数据态 + 入库态（前端状态盘用），另含 worker 就绪状态。"""
+    """各站登录态 + 数据态 + 入库态（前端状态盘用），另含 worker 就绪状态。
+
+    active_sites：本次会话实际挂载的站点（= ctx.sites_to_watch）。
+    调试模式（config.yaml debug.enabled）下仅挂载 target_site，未挂载站点
+    的 login_state 是 state.db 里上一会话的残留值，前端须以 active_sites 为准
+    判定"在线"，不能只看 login_state。
+    """
+    ctx = worker_state.get("ctx")
+    active_sites = list(ctx.sites_to_watch) if ctx is not None else []
     return {
         "worker_ready": worker_state["ready"],
         "worker_error": worker_state["error"],
+        "active_sites": active_sites,
         "sites": state_store.get_all_status(),
         "ingest": state_store.get_all_ingest_state(),
     }