Implement full SMTP Tester with premium UI and Backend

public/script.js

@@ -0,0 +1,67 @@
+function togglePassword() {
+    const passInput = document.getElementById('pass');
+    const type = passInput.getAttribute('type') === 'password' ? 'text' : 'password';
+    passInput.setAttribute('type', type);
+}
+
+document.getElementById('smtpForm').addEventListener('submit', async function(e) {
+    e.preventDefault();
+
+    const btn = document.getElementById('testBtn');
+    const spinner = btn.querySelector('.loading-spinner');
+    const btnText = btn.querySelector('.btn-text');
+    const resultsDiv = document.getElementById('results');
+    const statusDiv = document.getElementById('statusMessage');
+    const logOutput = document.getElementById('logOutput');
+
+    // Reset UI
+    resultsDiv.classList.add('hidden');
+    statusDiv.className = 'status-message';
+    statusDiv.textContent = '';
+    logOutput.textContent = '';
+    
+    // Set Loading State
+    btn.disabled = true;
+    spinner.classList.remove('hidden');
+    btnText.textContent = 'Testing...';
+
+    // Get Form Data
+    const formData = new FormData(this);
+    const data = Object.fromEntries(formData.entries());
+
+    try {
+        const response = await fetch('/api/test-smtp', {
+            method: 'POST',
+            headers: {
+                'Content-Type': 'application/json',
+            },
+            body: JSON.stringify(data),
+        });
+
+        const result = await response.json();
+
+        // Show Results
+        resultsDiv.classList.remove('hidden');
+
+        if (result.success) {
+            statusDiv.classList.add('status-success');
+            statusDiv.textContent = '✅ Success! Email Sent Successfully.';
+            logOutput.textContent = JSON.stringify(result.details, null, 2);
+        } else {
+            statusDiv.classList.add('status-error');
+            statusDiv.textContent = '❌ Error: ' + result.message;
+            logOutput.textContent = result.error || 'Unknown error occurred.';
+        }
+
+    } catch (error) {
+        resultsDiv.classList.remove('hidden');
+        statusDiv.classList.add('status-error');
+        statusDiv.textContent = '❌ Network Error';
+        logOutput.textContent = error.toString();
+    } finally {
+        // Reset Button
+        btn.disabled = false;
+        spinner.classList.add('hidden');
+        btnText.textContent = 'Test Configuration & Send Email';
+    }
+});