Make email service initialization asynchronous

Convert getEmailService() to async function and update all callers to use await.
Replace synchronous require() with dynamic import() for admin-config module.
Add SMTP config loading to admin configuration dialog.

server/api/admin/test-email.post.ts

@@ -49,7 +49,7 @@ export default defineEventHandler(async (event) => {
 
     // Get email service and send test email
     const { getEmailService } = await import('~/server/utils/email');
-    const emailService = getEmailService();
+    const emailService = await getEmailService();
     
     // Verify connection first
     const connectionOk = await emailService.verifyConnection();

server/api/auth/send-verification-email.post.ts

@@ -82,7 +82,7 @@ export default defineEventHandler(async (event) => {
 
     // Send verification email
     const { getEmailService } = await import('~/server/utils/email');
-    const emailService = getEmailService();
+      const emailService = await getEmailService();
 
     try {
       await emailService.sendWelcomeEmail(email, {

server/api/members/[id]/create-portal-account.post.ts

@@ -122,7 +122,7 @@ export default defineEventHandler(async (event) => {
       const { getEmailService } = await import('~/server/utils/email');
       const { generateEmailVerificationToken } = await import('~/server/utils/email-tokens');
       
-      const emailService = getEmailService();
+        const emailService = await getEmailService();
       const verificationToken = await generateEmailVerificationToken(keycloakId, member.email);
       const config = useRuntimeConfig();
       const verificationLink = `${config.public.domain}/api/auth/verify-email?token=${verificationToken}`;

server/api/registration.post.ts

@@ -141,7 +141,7 @@ export default defineEventHandler(async (event) => {
       const { getEmailService } = await import('~/server/utils/email');
       const { generateEmailVerificationToken } = await import('~/server/utils/email-tokens');
       
-      const emailService = getEmailService();
+      const emailService = await getEmailService();
       const verificationToken = await generateEmailVerificationToken(createdKeycloakId, body.email);
       const config = useRuntimeConfig();
       const verificationLink = `${config.public.domain}/api/auth/verify-email?token=${verificationToken}`;