fix: Remove double JSON parsing in handleHandshakeMsg

**Motivations :**
- Fix JSON parsing error in handleHandshakeMsg
- Message content is already parsed by validator

**Modifications :**
- Removed JSON.parse() call since parsedMsg is already an object
- Added comment explaining the change

**Pages affectées :**
- src/services/service.ts - Fixed double parsing issue

src/services/service.ts

@@ -2108,7 +2108,8 @@ export default class Services {
   // Handle the handshake message
   public async handleHandshakeMsg(url: string, parsedMsg: any) {
     try {
-      const handshakeMsg: HandshakeMessage = JSON.parse(parsedMsg);
+      // parsedMsg is already parsed by the validator, no need to JSON.parse again
+      const handshakeMsg: HandshakeMessage = parsedMsg;
       console.log('🔍 DEBUG: Handshake message received:', {
         url,
         hasSpAddress: !!handshakeMsg.sp_address,