build(config): update API endpoint to production URL and remove dev proxy

Changes the default API base URL from local development server (127.0.0.1:8080) to the production endpoint (bbs.littlelan.cn) and removes the Vite dev server proxy configuration, as the application now connects directly to the production API.

src/api/client.ts

@@ -2,7 +2,7 @@ import axios from 'axios'
 import { useAuthStore } from '@/stores/authStore'
 
 const apiClient = axios.create({
-  baseURL: import.meta.env.VITE_API_BASE_URL || 'http://127.0.0.1:8080/api/v1',
+  baseURL: import.meta.env.VITE_API_BASE_URL || 'https://bbs.littlelan.cn/api/v1',
   timeout: 10000,
   headers: {
     'Content-Type': 'application/json',