feat(core): the e-mail server after Java, measured against Java

SMTP on port 25 stores mails for the domain's accounts as Java reads
them anew and tells a local sender of unknown recipients; POP3 on port
110 hands them out. The mailboxes are in the snapshot and go back into
the project. EmailRun plays four stories over the network; MailCases
feeds Java's workers without one (26 cases, de and en). 18 cases name
Java bugs that the core does not take.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/core/src/index.ts

@@ -24,6 +24,8 @@ export * from './runtime/apps/echo.js';
 export * from './runtime/apps/web.js';
 export * from './runtime/apps/routerPages.js';
 export * from './runtime/apps/firewallSettings.js';
+export * from './runtime/apps/emailServer.js';
+export * from './runtime/email.js';
 export * from './runtime/http.js';
 export * from './util/equal.js';
 export * from './util/javaBase64.js';