feat: Implement proper trickle ICE support

Major improvements to connection establishment:

**Trickle ICE Implementation:**
- Send offer/answer to server IMMEDIATELY after creating SDP
- Don't wait for ICE gathering before sending offer/answer
- ICE candidates are now sent as they're discovered (true trickle ICE)
- Connection attempts can start with first candidates while more gather

**Removed Delays:**
- CreatingOfferState: No longer waits 10-15s for ICE before sending offer
- AnsweringState: No longer waits 10-15s for ICE before sending answer
- Answering state now takes ~50-200ms instead of 15+ seconds

**Code Organization:**
- Moved peer.ts to peer/index.ts directory structure
- Removed unused pendingCandidates buffering
- Removed unused waitForIceGathering methods
- Cleaned up timeout handling

**Breaking Changes:**
- "answering" state now transitions much faster to "exchanging-ice"
- ICE candidates start trickling immediately instead of in batches

This dramatically improves connection speed and follows WebRTC best practices.

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

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

src/rondevu.ts

@@ -1,6 +1,6 @@
 import { RondevuAuth, Credentials, FetchFunction } from './auth.js';
 import { RondevuOffers } from './offers.js';
-import RondevuPeer from './peer.js';
+import RondevuPeer from './peer/index.js';
 
 export interface RondevuOptions {
   /**