Extend browser admin lifecycle actions

Support browser reboot and HTTPS stop through deferred control, plus
exact
`web certificate rotate --force` handoff to the dispatcher. Add typed
request
validation and focused boundary and lifecycle coverage.

src/system_console.c

@@ -54,7 +54,7 @@ static int command_reboot(int argc, char **argv)
             printf("Could not schedule reboot: %s\n", esp_err_to_name(error));
             return 1;
         }
-        printf("Reboot scheduled after SSH output drains; unsaved changes will be lost.\n");
+        printf("Reboot scheduled after console output drains; unsaved changes will be lost.\n");
         return 0;
     }
     printf("Rebooting now; unsaved RAM-only configuration changes will be lost.\n");