🎨 Palette: Add accessible loading states to auth forms

.Jules/palette.md

@@ -0,0 +1,6 @@
+## 2026-06-10 - [Initial UX check]
+**Learning:** Checking for standard UX loading states.
+**Action:** Need to add loading state to buttons.
+## 2026-06-10 - [Accessible Async Loading States]
+**Learning:** Vanilla JS forms need explicit UI feedback during async operations, but standard DOM methods like `e.target.querySelector` can fail if the click intercepted by child elements.
+**Action:** Used `e.submitter` to robustly capture the submitting button, allowing temporary text modification (`⏳ Logging in...`), `disabled` state, and `aria-busy` attribute implementation within a `try/finally` block to ensure robust cleanup without adding custom CSS.

web-demo/js/app.js

@@ -142,6 +142,13 @@ class ClimaAI {
 
     async handleLogin(e) {
         e.preventDefault();
+        const submitBtn = e.submitter;
+        if (submitBtn) {
+            submitBtn.disabled = true;
+            submitBtn.setAttribute('aria-busy', 'true');
+            submitBtn.dataset.originalText = submitBtn.innerHTML;
+            submitBtn.innerHTML = '⏳ Logging in...';
+        }
         const email = document.getElementById('loginEmail').value;
         const password = document.getElementById('loginPassword').value;
 
@@ -155,11 +162,24 @@ class ClimaAI {
             this.checkSubscription();
         } catch (error) {
             this.showToast(error.message || 'Login failed', 'error');
+        } finally {
+            if (submitBtn) {
+                submitBtn.disabled = false;
+                submitBtn.removeAttribute('aria-busy');
+                submitBtn.innerHTML = submitBtn.dataset.originalText || submitBtn.innerHTML;
+            }
         }
     }
 
     async handleRegister(e) {
         e.preventDefault();
+        const submitBtn = e.submitter;
+        if (submitBtn) {
+            submitBtn.disabled = true;
+            submitBtn.setAttribute('aria-busy', 'true');
+            submitBtn.dataset.originalText = submitBtn.innerHTML;
+            submitBtn.innerHTML = '⏳ Signing up...';
+        }
         const name = document.getElementById('registerName').value;
         const email = document.getElementById('registerEmail').value;
         const password = document.getElementById('registerPassword').value;
@@ -174,6 +194,12 @@ class ClimaAI {
             this.checkSubscription();
         } catch (error) {
             this.showToast(error.message || 'Registration failed', 'error');
+        } finally {
+            if (submitBtn) {
+                submitBtn.disabled = false;
+                submitBtn.removeAttribute('aria-busy');
+                submitBtn.innerHTML = submitBtn.dataset.originalText || submitBtn.innerHTML;
+            }
         }
     }