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/handlers/network.py

@@ -21,7 +21,9 @@ from daemon.iface import (
     POST_NETWORK_SYSCTL_SET,
 )
 from daemon.server import NotFoundError, refresh_state, registry
-from lib.common import run, validate_interface_name
+from lib.common import _APPLY_HASH_KEY, config_hash, run, validate_interface_name
+from lib.dnsmasq import get_config as _get_dm_cfg
+from lib.dnsmasq import save_config as _save_dm_cfg
 from lib.dnsmasq import set_upstreams
 from lib.network import (
     KNOWN_INTERFACE_KEYS,
@@ -195,6 +197,10 @@ def save_interface(_request: Any, body: dict[str, Any] | None) -> dict[str, Any]
         )
 
     logger.info("Interface '%s' config saved (applied=%s)", name, deployed)
+    if deployed:
+        cfg_after = get_config()
+        cfg_after[_APPLY_HASH_KEY] = config_hash(cfg_after)
+        save_config(cfg_after)
     sync_result = bus.emit(
         SyncEvent(
             "network", "config_saved", {"action": "interface_saved", "interface": name}
@@ -258,10 +264,17 @@ def apply_all(_request: Any, _body: Any) -> dict[str, Any]:
         upstreams = collect_upstream_dns(cfg)
         if upstreams:
             set_upstreams(upstreams)
+            # Update dnsmasq apply hash so pending-changes detection stays correct
+            dm_cfg = _get_dm_cfg()
+            dm_cfg[_APPLY_HASH_KEY] = config_hash(dm_cfg)
+            _save_dm_cfg(dm_cfg)
             logger.info("Synced %d DNS upstreams to dnsmasq", len(upstreams))
     except Exception:
         logger.warning("Failed to sync DNS upstreams to dnsmasq", exc_info=True)
 
+    cfg_after = get_config()
+    cfg_after[_APPLY_HASH_KEY] = config_hash(cfg_after)
+    save_config(cfg_after)
     sync_result = bus.emit(
         SyncEvent("network", "config_saved", {"action": "config_applied"})
     )