Add update-vendor.sh symlink support, unify install.sh vendor flow

- update-vendor.sh now creates webui/vendor symlinks (htm.js)
- install.sh calls update-vendor.sh after package install
- Add vendor/.empty and webui/vendor/.empty as directory placeholders in git

daemon/iface.py

@@ -146,6 +146,8 @@ GET_STATUS_ALL: Endpoint = _ep("GET", "/status/all")
 POST_STATUS_REFRESH: Endpoint = _ep("POST", "/status/refresh")
 GET_WS: Endpoint = _ep("GET", "/ws")
 POST_BATCH: Endpoint = _ep("POST", "/batch")
+GET_STATUS_PENDING: Endpoint = _ep("GET", "/status/pending")
+POST_STATUS_APPLY_ALL: Endpoint = _ep("POST", "/status/apply-all")
 
 # Collect all endpoint module-level constants for __all__ verification
 _all_endpoints = [