fix(F006-W18): LoginView 2 处永久修复 /api 前缀

改前: line 48 captchaUrl = /auth/captcha (img src 不走 axios baseURL)
      line 68 axios.post(/auth/oauth/token) (不走 http 实例 baseURL)
      巨变数字 nginx 只代理 /api/ 前缀, /auth/* 全 404

改后: line 48 /api/auth/captcha
      line 68 /api/auth/oauth/token

验证 (0 命中才通过):
  grep /auth/captcha dist/*.js | grep -v /api  → 0 ✅
  grep /auth/oauth dist/*.js | grep -v /api   → 0 ✅

src/modules/auth/LoginView.vue

@@ -65,7 +65,7 @@ async function onLogin() {
   loading.value = true
   try {
     const res = await axios.post(
-      '/auth/oauth/token',
+      '/api/auth/oauth/token',
       qs.stringify({ ...form, grant_type: 'password' }),
       {
         headers: {