feat(i18n): initialize internationalization and update Vite config for locale handling

- Added `initI18n` function call in `main.tsx` to bootstrap internationalization before rendering the app.
- Updated Vite configuration to handle specific locale files for English and Chinese.

webapp/src/lib/api/auth.ts

@@ -382,12 +382,37 @@ export async function getPasswordHint(email: string): Promise<{ masterPasswordHi
 
 export function createAuthedFetch(getSession: () => SessionState | null, setSession: SessionSetter) {
   return async function authedFetch(input: string, init: RequestInit = {}): Promise<Response> {
+    const retryableRequest = async (headers: Headers): Promise<Response> => {
+      const maxAttempts = 3;
+      let lastError: unknown;
+      for (let attempt = 0; attempt < maxAttempts; attempt += 1) {
+        try {
+          const response = await fetch(input, { ...init, headers });
+          if (response.status !== 429 && (response.status < 500 || response.status >= 600)) {
+            return response;
+          }
+          lastError = new Error(`HTTP ${response.status}`);
+          if (attempt === maxAttempts - 1) {
+            return response;
+          }
+        } catch (error) {
+          lastError = error;
+          if (attempt === maxAttempts - 1) {
+            throw error;
+          }
+        }
+        const delayMs = 250 * (2 ** attempt) + Math.floor(Math.random() * 120);
+        await new Promise((resolve) => window.setTimeout(resolve, delayMs));
+      }
+      throw lastError instanceof Error ? lastError : new Error('Request failed');
+    };
+
     const session = getSession();
     if (!session?.accessToken) throw new Error('Unauthorized');
     const headers = new Headers(init.headers || {});
     headers.set('Authorization', `Bearer ${session.accessToken}`);
 
-    let resp = await fetch(input, { ...init, headers });
+    let resp = await retryableRequest(headers);
     if (resp.status !== 401 || (!session.refreshToken && session.authMode !== 'web-cookie')) return resp;
 
     const refreshed = await refreshAccessToken(session);
@@ -410,7 +435,7 @@ export function createAuthedFetch(getSession: () => SessionState | null, setSess
 
     const retryHeaders = new Headers(init.headers || {});
     retryHeaders.set('Authorization', `Bearer ${nextSession.accessToken}`);
-    resp = await fetch(input, { ...init, headers: retryHeaders });
+    resp = await retryableRequest(retryHeaders);
     return resp;
   };
 }