Add WebRTC polyfill support for Node.js environments

Allow users to pass WebRTC polyfills (RTCPeerConnection, RTCIceCandidate) through RondevuOptions instead of manually setting global variables. The client now automatically applies these to globalThis when provided.

This simplifies Node.js integration:
- Before: Users had to manually set globalThis.RTCPeerConnection
- After: Pass rtcPeerConnection and rtcIceCandidate options

Example:
  const rondevu = await Rondevu.connect({
    apiUrl: 'https://api.example.com',
    username: 'alice',
    cryptoAdapter: new NodeCryptoAdapter(),
    rtcPeerConnection: wrtc.RTCPeerConnection,
    rtcIceCandidate: wrtc.RTCIceCandidate
  })

src/rondevu.ts

@@ -57,6 +57,9 @@ export interface RondevuOptions {
     batching?: BatcherOptions | false  // Optional, defaults to enabled with default options
     iceServers?: IceServerPreset | RTCIceServer[]  // Optional: preset name or custom STUN/TURN servers
     debug?: boolean  // Optional: enable debug logging (default: false)
+    // WebRTC polyfills for Node.js environments (e.g., wrtc)
+    rtcPeerConnection?: typeof RTCPeerConnection
+    rtcIceCandidate?: typeof RTCIceCandidate
 }
 
 export interface OfferContext {
@@ -167,6 +170,8 @@ export class Rondevu {
     private batchingOptions?: BatcherOptions | false
     private iceServers: RTCIceServer[]
     private debugEnabled: boolean
+    private rtcPeerConnection?: typeof RTCPeerConnection
+    private rtcIceCandidate?: typeof RTCIceCandidate
 
     // Service management
     private currentService: string | null = null
@@ -188,7 +193,9 @@ export class Rondevu {
         iceServers: RTCIceServer[],
         cryptoAdapter?: CryptoAdapter,
         batchingOptions?: BatcherOptions | false,
-        debugEnabled = false
+        debugEnabled = false,
+        rtcPeerConnection?: typeof RTCPeerConnection,
+        rtcIceCandidate?: typeof RTCIceCandidate
     ) {
         this.apiUrl = apiUrl
         this.username = username
@@ -198,6 +205,8 @@ export class Rondevu {
         this.cryptoAdapter = cryptoAdapter
         this.batchingOptions = batchingOptions
         this.debugEnabled = debugEnabled
+        this.rtcPeerConnection = rtcPeerConnection
+        this.rtcIceCandidate = rtcIceCandidate
 
         this.debug('Instance created:', {
             username: this.username,
@@ -230,6 +239,14 @@ export class Rondevu {
     static async connect(options: RondevuOptions): Promise<Rondevu> {
         const username = options.username || Rondevu.generateAnonymousUsername()
 
+        // Apply WebRTC polyfills to global scope if provided (Node.js environments)
+        if (options.rtcPeerConnection) {
+            globalThis.RTCPeerConnection = options.rtcPeerConnection as any
+        }
+        if (options.rtcIceCandidate) {
+            globalThis.RTCIceCandidate = options.rtcIceCandidate as any
+        }
+
         // Handle preset string or custom array
         let iceServers: RTCIceServer[]
         if (typeof options.iceServers === 'string') {
@@ -277,7 +294,9 @@ export class Rondevu {
             iceServers,
             options.cryptoAdapter,
             options.batching,
-            options.debug || false
+            options.debug || false,
+            options.rtcPeerConnection,
+            options.rtcIceCandidate
         )
     }