FIX: Authentication middleware for custom Keycloak auth

##  **Fixed 502 Error After Login:**

### **Issue:**
- After successful Keycloak authentication, users got 502 Bad Gateway error
- Middleware was still trying to use removed useOidcAuth() composable
- This caused the app to crash when accessing dashboard

### **Solution:**
-  Replaced useOidcAuth() with direct session API call
-  Uses /api/auth/session endpoint to check authentication
-  Maintains dual auth support (Directus + Keycloak)
-  Added proper error handling to prevent crashes

### **Authentication Flow Now:**
1. **Check Directus auth** first (existing users)
2. **Check custom Keycloak session** via API call
3. **Allow access** if either authentication succeeds
4. **Redirect to login** if no authentication found

### **Files Changed:**
- middleware/authentication.ts - Updated to use custom auth system

##  **Result:**
The complete authentication flow should now work:
1.  Login via Keycloak SSO
2.  Token exchange and session creation
3.  Middleware validates session properly
4.  Dashboard loads without 502 errors

##  **Ready to Test:**
Deploy and test the complete SSO flow - should work end-to-end!

middleware/authentication.ts

@@ -19,7 +19,7 @@ export default defineNuxtRouteMiddleware(async (to) => {
         const user = await fetchUser();
         setUser(user.value);
       } catch (error) {
-        // Directus auth failed, continue to check OIDC
+        // Directus auth failed, continue to check custom Keycloak auth
       }
     }
 
@@ -28,12 +28,15 @@ export default defineNuxtRouteMiddleware(async (to) => {
       return;
     }
 
-    // Check OIDC auth (Keycloak)
-    const { user: oidcUser, loggedIn } = useOidcAuth();
-    
-    if (loggedIn.value && oidcUser.value) {
-      // User authenticated with Keycloak via OIDC
-      return;
+    // Check custom Keycloak auth via session API
+    try {
+      const sessionData = await $fetch('/api/auth/session') as any;
+      if (sessionData.authenticated && sessionData.user) {
+        // User authenticated with Keycloak
+        return;
+      }
+    } catch (error) {
+      // Session check failed, continue to redirect
     }
 
     // No authentication found, redirect to login