fix(gateway): explain ignored restart signal

Add actionable operator guidance when an unauthorized SIGUSR1 gateway restart is ignored because unmanaged restart is disabled.

The change is log-only: restart authorization and scheduling semantics are unchanged, and the existing run-loop test now asserts both the reason warning and the recovery hint.

Refs #79577
Refs #78110
Refs #82433

Co-authored-by: wAngByg <281221101+wAngByg@users.noreply.github.com>

src/cli/gateway-cli/run-loop.test.ts

@@ -1205,6 +1205,13 @@ describe("runGatewayLoop", () => {
       expect(gatewayLog.warn).toHaveBeenCalledWith(
         "SIGUSR1 restart ignored (not authorized; commands.restart=false or use gateway tool).",
       );
+      expect(gatewayLog.warn).toHaveBeenCalledTimes(2);
+      expect(gatewayLog.warn).toHaveBeenNthCalledWith(
+        2,
+        "An unauthorized SIGUSR1 restart signal was received and ignored. " +
+          "If a pending gateway restart needs to be applied, run `openclaw gateway restart` " +
+          "or restart the gateway through your service manager.",
+      );
     });
   });