feat(admin): manage server updates and local configuration

packages/i18n/locales/en/errors.json

@@ -101,5 +101,21 @@
     "invalid_tracks": "Tracks must be unique and exist in the library",
     "too_large": "Maximum 2000 tracks and 2000 description characters",
     "conflict": "This playlist changed on another device. Close the editor and try again with the refreshed data."
+  },
+  "management": {
+    "unavailable": "Server management agent is unavailable. Run sudo bash deploy/install-management.sh on the server and check pipu-management.service.",
+    "timeout": "The agent timed out. Check operation status before retrying.",
+    "busy": "A server operation is already running. Wait for it to finish.",
+    "source_invalid": "Check source names and URLs. Embedded passwords and tokens are not supported.",
+    "source_unavailable": "The repository is unavailable from the server.",
+    "target_invalid": "The selected version is unavailable or changed. Refresh the list and try again.",
+    "no_releases": "No stable release tags were found.",
+    "config_conflict": "Another administrator changed the configuration. Reload the page and repeat your edits.",
+    "config_invalid": "Invalid value or Compose configuration. Changes were not saved.",
+    "config_readonly": "This setting cannot be changed in the interface.",
+    "agent_error": "The agent could not complete the operation. Check journalctl -u pipu-management.",
+    "request_expired": "The request expired. Check operation status before retrying.",
+    "request_invalid": "Invalid server management request.",
+    "operation_invalid": "Unsupported server management operation."
   }
 }