Add durable WebRTC connections with auto-reconnect and message buffering (v0.18.8)

- Add connection state machine with proper lifecycle management
- Implement automatic reconnection with exponential backoff
- Add message buffering during disconnections
- Create RondevuConnection base class with state tracking
- Create OffererConnection and AnswererConnection classes
- Fix ICE polling lifecycle (now stops when connected)
- Add fillOffers() semaphore to prevent exceeding maxOffers
- Implement answer fingerprinting to prevent duplicate processing
- Add dual ICE state monitoring (iceConnectionState + connectionState)
- Fix data channel handler timing issues
- Add comprehensive event system (20+ events)
- Add connection timeouts and proper cleanup

Breaking changes:
- connectToService() now returns AnswererConnection instead of ConnectionContext
- connection:opened event signature changed: (offerId, dc) → (offerId, connection)
- Direct DataChannel access replaced with connection wrapper API

See MIGRATION.md for upgrade guide.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@xtr-dev/rondevu-client",
-  "version": "0.18.7",
+  "version": "0.18.8",
   "description": "TypeScript client for Rondevu with durable WebRTC connections, automatic reconnection, and message queuing",
   "type": "module",
   "main": "dist/index.js",