add logging to main auth

public/js/main.js

@@ -23,12 +23,23 @@ let authToken = null;
 
 // --- EVENT HANDLERS (The "Logic") ---
 async function handleAuthSubmit(e) {
+    console.log("1. Form submitted, handleAuthSubmit function started."); // Checkpoint 1
     e.preventDefault();
+
     const username = e.target.elements.username.value;
     const password = e.target.elements.password.value;
+    console.log(`2. Attempting to log in user: ${username}`); // Checkpoint 2
+
     const res = await apiCall('/login', 'POST', { username, password });
-    if (res.success) {
+    console.log("3. Received response from apiCall:", res); // Checkpoint 3
+
+    if (res && res.success) {
+        console.log("4. Login was successful, calling initializeApp()."); // Checkpoint 4
         initializeApp();
+    } else {
+        console.error("5. Login failed. Server response:", res); // Checkpoint 5
+        // We can add a user-facing error message here
+        showMessage(res?.data?.message || 'Login failed. Please check your credentials.', 'error');
     }
 }