Complete email router implementation and documentation

- Cleaned up interface definitions to only include implemented features
- Updated readme.md with comprehensive route-based configuration examples
- Added common email routing patterns and troubleshooting guide
- Removed legacy DomainRouter and IDomainRule interfaces
- Updated all imports and exports to use new EmailRouter system
- Verified build and core functionality tests pass

The match/action pattern implementation is now complete and production-ready.

ts/classes.dcrouter.ts

@@ -5,7 +5,6 @@ import * as paths from './paths.js';
 
 // Import the email server and its configuration
 import { UnifiedEmailServer, type IUnifiedEmailServerOptions } from './mail/routing/classes.unified.email.server.js';
-import type { IDomainRule, EmailProcessingMode } from './mail/routing/classes.email.config.js';
 import type { IEmailRoute } from './mail/routing/interfaces.js';
 import { logger } from './logger.js';
 // Import the email configuration helpers directly from mail/delivery
@@ -596,6 +595,6 @@ export class DcRouter {
 }
 
 // Re-export email server types for convenience
-export type { IUnifiedEmailServerOptions, IDomainRule, EmailProcessingMode };
+export type { IUnifiedEmailServerOptions };
 
 export default DcRouter;