Fix login authentication flow and improve proxy configuration

- Refactor login page to use auth composable for better state management
- Update nginx proxy settings with proper timeouts and buffering
- Improve PWA service worker caching strategy for API calls
- Add debug files and documentation for login troubleshooting

pages/login.vue

@@ -122,8 +122,10 @@ definePageMeta({
   layout: false
 });
 
+// Use the auth composable
+const { user, login, loading: authLoading, error: authError, checkAuth } = useAuth();
+
 // Check if user is already authenticated
-const { user } = useAuth();
 if (user.value) {
   await navigateTo('/dashboard');
 }
@@ -137,7 +139,6 @@ const credentials = ref({
 
 const showPassword = ref(false);
 const showForgotPassword = ref(false);
-const loading = ref(false);
 const loginError = ref('');
 const errors = ref({
   username: '',
@@ -147,6 +148,7 @@ const errors = ref({
 const loginForm = ref();
 
 // Computed
+const loading = computed(() => authLoading.value);
 const isFormValid = computed(() => {
   return credentials.value.username.length > 0 && 
          credentials.value.password.length > 0 && 
@@ -174,33 +176,22 @@ const validateForm = () => {
 const handleLogin = async () => {
   if (!validateForm()) return;
 
-  loading.value = true;
   loginError.value = '';
 
   try {
-    const response = await $fetch<{
-      success: boolean;
-      redirectTo?: string;
-      user?: any;
-    }>('/api/auth/direct-login', {
-      method: 'POST',
-      body: {
-        username: credentials.value.username,
-        password: credentials.value.password,
-        rememberMe: credentials.value.rememberMe
-      }
+    const result = await login({
+      username: credentials.value.username,
+      password: credentials.value.password,
+      rememberMe: credentials.value.rememberMe
     });
 
-    if (response.success) {
-      // Force a page reload to ensure the session cookie is properly read
-      // This is more reliable than trying to update the auth state manually
-      window.location.href = response.redirectTo || '/dashboard';
+    if (!result.success) {
+      loginError.value = result.error || 'Login failed. Please check your credentials and try again.';
     }
+    // If successful, the login method will handle the redirect
   } catch (error: any) {
     console.error('Login error:', error);
-    loginError.value = error.data?.message || 'Login failed. Please check your credentials and try again.';
-  } finally {
-    loading.value = false;
+    loginError.value = authError.value || 'Login failed. Please check your credentials and try again.';
   }
 };