Refactor: Send/receive ICE candidates as complete objects

- Update to send full RTCIceCandidateInit objects instead of partial data
- Simplify API by using JSON serialization
- Include usernameFragment field
- More maintainable and future-proof

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

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

src/connection.ts

@@ -1,4 +1,4 @@
-import { RondevuOffers } from './offers.js';
+import { RondevuOffers, RTCIceCandidateInit } from './offers.js';
 
 /**
  * Events emitted by RondevuConnection
@@ -60,11 +60,7 @@ export class RondevuConnection {
   private lastIceTimestamp: number = Date.now();
   private eventListeners: Map<keyof RondevuConnectionEvents, Set<Function>> = new Map();
   private dataChannel?: RTCDataChannel;
-  private pendingIceCandidates: Array<{
-    candidate: string;
-    sdpMid: string | null;
-    sdpMLineIndex: number | null;
-  }> = [];
+  private pendingIceCandidates: RTCIceCandidateInit[] = [];
 
   /**
    * Current connection state
@@ -107,10 +103,12 @@ export class RondevuConnection {
   private setupPeerConnection(): void {
     this.pc.onicecandidate = async (event) => {
       if (event.candidate) {
-        const candidateData = {
+        // Convert RTCIceCandidate to RTCIceCandidateInit (plain object)
+        const candidateData: RTCIceCandidateInit = {
           candidate: event.candidate.candidate,
           sdpMid: event.candidate.sdpMid,
           sdpMLineIndex: event.candidate.sdpMLineIndex,
+          usernameFragment: event.candidate.usernameFragment,
         };
 
         if (this.offerId) {
@@ -282,14 +280,10 @@ export class RondevuConnection {
           this.lastIceTimestamp
         );
 
-        for (const candidate of candidates) {
-          // Create ICE candidate with all fields
-          await this.pc.addIceCandidate(new RTCIceCandidate({
-            candidate: candidate.candidate,
-            sdpMid: candidate.sdpMid ?? undefined,
-            sdpMLineIndex: candidate.sdpMLineIndex ?? undefined,
-          }));
-          this.lastIceTimestamp = candidate.createdAt;
+        for (const cand of candidates) {
+          // Use the candidate object directly - it's already RTCIceCandidateInit
+          await this.pc.addIceCandidate(new RTCIceCandidate(cand.candidate));
+          this.lastIceTimestamp = cand.createdAt;
         }
       } catch (err) {
         console.error('Error polling for ICE candidates:', err);

src/offers.ts

@@ -24,10 +24,18 @@ export interface Offer {
   answeredAt?: number;
 }
 
+/**
+ * RTCIceCandidateInit interface for environments without native WebRTC types
+ */
+export interface RTCIceCandidateInit {
+  candidate?: string;
+  sdpMid?: string | null;
+  sdpMLineIndex?: number | null;
+  usernameFragment?: string | null;
+}
+
 export interface IceCandidate {
-  candidate: string;
-  sdpMid: string | null;
-  sdpMLineIndex: number | null;
+  candidate: RTCIceCandidateInit; // Full candidate object
   peerId: string;
   role: 'offerer' | 'answerer';
   createdAt: number;
@@ -282,11 +290,7 @@ export class RondevuOffers {
    */
   async addIceCandidates(
     offerId: string,
-    candidates: Array<{
-      candidate: string;
-      sdpMid?: string | null;
-      sdpMLineIndex?: number | null;
-    }>
+    candidates: RTCIceCandidateInit[]
   ): Promise<void> {
     const response = await this.fetchFn(`${this.baseUrl}/offers/${encodeURIComponent(offerId)}/ice-candidates`, {
       method: 'POST',