fix: add test-email endpoint for SMTP diagnostics

POST /api/admin/test-email — superadmin only, returns exact SMTP
host/port/error so we can diagnose why notifications aren't delivered.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/server.js

@@ -640,6 +640,28 @@ app.get('/api/health', async (req, res) => {
   });
 });
 
+// ─── EMAIL TEST ─────────────────────────────────────────────────
+
+app.post('/api/admin/test-email', requireAuth, async (req, res) => {
+  if (req.session.userRole !== 'superadmin') return res.status(403).json({ error: 'Superadmin only' });
+  const to = req.body.to || req.session.userEmail;
+  if (!to) return res.status(400).json({ error: 'No recipient — pass { "to": "email@example.com" }' });
+  const { sendMail, getSmtpConfig } = require('./mail');
+  const config = getSmtpConfig();
+  if (!config) return res.status(503).json({ error: 'SMTP not configured', env: { server: !!process.env.CLOUDRON_MAIL_SMTP_SERVER || !!process.env.MAIL_SMTP_SERVER } });
+  try {
+    const info = await sendMail({
+      to,
+      subject: 'Rawaj — Test Email',
+      html: '<p>If you received this, email delivery is working correctly.</p>',
+      text: 'If you received this, email delivery is working correctly.',
+    });
+    res.json({ success: true, to, messageId: info?.messageId, smtp: { host: config.host, port: config.port, from: config.from } });
+  } catch (err) {
+    res.status(500).json({ success: false, error: err.message, code: err.code, smtp: { host: config.host, port: config.port } });
+  }
+});
+
 // ─── SETUP ROUTES ───────────────────────────────────────────────
 
 app.get('/api/setup/status', async (req, res) => {