feat: v0.9.0 - durable WebRTC connections with automatic reconnection

Major refactor replacing low-level APIs with high-level durable connections.

New Features:
- Automatic reconnection with exponential backoff (1s → 2s → 4s → ... max 30s)
- Message queuing during disconnections
- Durable channels that survive connection drops
- TTL auto-refresh for services (refreshes at 80% of TTL by default)
- Full configuration of timeouts, retry limits, and queue sizes

New API:
- client.exposeService() - Create durable service with automatic TTL refresh
- client.connect() - Create durable connection with automatic reconnection
- client.connectByUuid() - Connect by service UUID
- DurableChannel - Event-based channel wrapper with message queuing
- DurableConnection - Connection manager with reconnection logic
- DurableService - Service manager with TTL auto-refresh

Files Added:
- src/durable/types.ts - Type definitions and enums
- src/durable/reconnection.ts - Exponential backoff utilities
- src/durable/channel.ts - DurableChannel class (358 lines)
- src/durable/connection.ts - DurableConnection class (441 lines)
- src/durable/service.ts - DurableService class (329 lines)
- MIGRATION.md - Comprehensive migration guide

Files Removed:
- src/services.ts - Replaced by DurableService
- src/discovery.ts - Replaced by DurableConnection

BREAKING CHANGES:
- Removed: client.services.*, client.discovery.*, client.createPeer()
- Added: client.exposeService(), client.connect(), client.connectByUuid()
- Handler signature: (channel, peer, connectionId?) → (channel, connectionId)
- Event handlers: .onmessage → .on('message')
- Services: Must call service.start() to begin accepting connections
- Connections: Must call connection.connect() to establish connection

src/service-pool.ts

@@ -2,7 +2,6 @@ import { RondevuOffers, Offer } from './offers.js';
 import { RondevuUsername } from './usernames.js';
 import RondevuPeer from './peer/index.js';
 import { OfferPool, AnsweredOffer } from './offer-pool.js';
-import { ServiceHandle } from './services.js';
 
 /**
  * Connection information for tracking active connections
@@ -73,9 +72,21 @@ export interface ServicePoolOptions {
 }
 
 /**
- * Extended service handle with pool-specific methods
+ * Service handle with pool-specific methods
  */
-export interface PooledServiceHandle extends ServiceHandle {
+export interface PooledServiceHandle {
+  /** Service ID */
+  serviceId: string;
+
+  /** Service UUID */
+  uuid: string;
+
+  /** Offer ID */
+  offerId: string;
+
+  /** Unpublish the service */
+  unpublish: () => Promise<void>;
+
   /** Get current pool status */
   getStatus: () => PoolStatus;