docs(tsup): update build config comments and fix jsx import extensions

src/core/email/templates/index.js

@@ -1 +1 @@
-export { BaseLayout } from './BaseLayout.jsx';
+export { BaseLayout } from './BaseLayout.js';

src/features/auth/email.js

@@ -1,9 +1,9 @@
 import { render } from '@react-email/components';
 import { fail, info } from '@zen/core/shared/logger';
 import { sendEmail } from '@zen/core/email';
-import { VerificationEmail } from './templates/VerificationEmail.jsx';
-import { PasswordResetEmail } from './templates/PasswordResetEmail.jsx';
-import { PasswordChangedEmail } from './templates/PasswordChangedEmail.jsx';
+import { VerificationEmail } from './templates/VerificationEmail.js';
+import { PasswordResetEmail } from './templates/PasswordResetEmail.js';
+import { PasswordChangedEmail } from './templates/PasswordChangedEmail.js';
 
 export { createEmailVerification, verifyEmailToken, createPasswordReset, verifyResetToken, deleteResetToken }
   from '../../core/users/verifications.js';