fix restart failing under non-root

restart_frigate() called psutil.Process(1).terminate() to signal s6-svscan, but s6-svscan runs as root while frigate runs as uid 1000, so the call raised AccessDenied. That exception escaped every caller: the UI restart button dropped its websocket client, MQTT restart and Save & Restart just logged and did nothing, and the watchdog crashed its own monitoring thread on a dead detector. This catches AccessDenied and falls through to the existing SIGINT branch, which exits the process for s6 to restart it.

frigate/util/services.py

@@ -35,12 +35,19 @@ logger = logging.getLogger(__name__)
 
 def restart_frigate():
     proc = psutil.Process(1)
+
     # if this is running via s6, sigterm pid 1
     if proc.name() == "s6-svscan":
-        proc.terminate()
+        try:
+            proc.terminate()
+            return
+        except psutil.AccessDenied:
+            # frigate runs unprivileged, so it cannot signal root's s6-svscan.
+            # exiting this process instead runs frigate/finish, which halts s6
+            logger.debug("Not permitted to signal s6-svscan, exiting instead")
+
     # otherwise, just try and exit frigate
-    else:
-        os.kill(os.getpid(), signal.SIGINT)
+    os.kill(os.getpid(), signal.SIGINT)
 
 
 def print_stack(sig, frame):