🎨 Palette: Add loading states for auth form submissions

.Jules/palette.md

@@ -0,0 +1,4 @@
+## 2024-05-17 - Async Form Submission State
+
+**Learning:** When dealing with native HTML form submissions triggered asynchronously, relying purely on the submit event isn't enough because the exact button clicked (`e.submitter`) is only available immediately. If there are loading state resets after `await`, using `e.submitter.innerHTML` ensures text and icons are restored correctly, and a `try/finally` block guarantees restoration even if the async call fails.
+**Action:** Always capture `e.submitter` state (original text/icons) immediately at the start of the submit handler, show a clear loading indicator, and restore the original state in a `finally` block to ensure a robust user experience during async API calls.

web-demo/js/app.js

@@ -145,6 +145,14 @@ class ClimaAI {
         const email = document.getElementById('loginEmail').value;
         const password = document.getElementById('loginPassword').value;
 
+        let originalText = '';
+        if (e.submitter) {
+            originalText = e.submitter.innerHTML;
+            e.submitter.innerHTML = '⏳ Loading...';
+            e.submitter.disabled = true;
+            e.submitter.style.opacity = '0.7';
+        }
+
         try {
             this.showToast('Logging in...', 'info');
             const response = await api.login(email, password);
@@ -155,6 +163,12 @@ class ClimaAI {
             this.checkSubscription();
         } catch (error) {
             this.showToast(error.message || 'Login failed', 'error');
+        } finally {
+            if (e.submitter) {
+                e.submitter.innerHTML = originalText;
+                e.submitter.disabled = false;
+                e.submitter.style.opacity = '1';
+            }
         }
     }
 
@@ -164,6 +178,14 @@ class ClimaAI {
         const email = document.getElementById('registerEmail').value;
         const password = document.getElementById('registerPassword').value;
 
+        let originalText = '';
+        if (e.submitter) {
+            originalText = e.submitter.innerHTML;
+            e.submitter.innerHTML = '⏳ Loading...';
+            e.submitter.disabled = true;
+            e.submitter.style.opacity = '0.7';
+        }
+
         try {
             this.showToast('Creating account...', 'info');
             const response = await api.register(email, password, name);
@@ -174,6 +196,12 @@ class ClimaAI {
             this.checkSubscription();
         } catch (error) {
             this.showToast(error.message || 'Registration failed', 'error');
+        } finally {
+            if (e.submitter) {
+                e.submitter.innerHTML = originalText;
+                e.submitter.disabled = false;
+                e.submitter.style.opacity = '1';
+            }
         }
     }