Add JSDoc documentation and file headers to all source files

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/module/apiError.js

@@ -1,15 +1,30 @@
+// The Lucia project.
+// Copyright 2023-2026 DSP, inc.  All rights reserved.
+// Authors:
+//   chiayin.kuo@dsp.im (chiayin), 2023/1/31
+//   imacat.yang@dsp.im (imacat), 2023/9/23
+//   cindy.chang@dsp.im (Cindy Chang), 2024/5/30
+/** @module apiError Centralized API error handler with toast notifications. */
+
 import { useLoadingStore } from '@/stores/loading';
 import {useToast} from 'vue-toast-notification';
 import 'vue-toast-notification/dist/theme-sugar.css';
 
-// Delay loading and toast
+/**
+ * Returns a promise that resolves after the specified milliseconds.
+ * @param {number} [s=0] - The delay in milliseconds.
+ * @returns {Promise<void>} A promise that resolves after the delay.
+ */
 const delay = (s = 0) =>  new Promise((resolve, reject) => setTimeout(resolve, s));
 
 /**
- * API catch error function.
- * 401 errors are handled by the axios response interceptor in api/client.js.
- * @param   {object} error 後端 ERROR
- * @param   {string} toastMessage Toast 的提示文字
+ * Handles API errors by showing a loading spinner followed by a toast
+ * notification. 401 errors are handled by the axios response interceptor
+ * in api/client.js.
+ *
+ * @param {Object} error - The error object from the API call.
+ * @param {string} toastMessage - The message to display in the toast.
+ * @returns {Promise<void>}
  */
 export default async function apiError(error, toastMessage) {
   const loading = useLoadingStore();