fix: resolve P2P data plane decrypt failure and improve test environment

- Fix key derivation in both sdk/agent.go and internal/vl1/noise.go:
  sort public keys before hashing, use shared key for send/recv
- Adjust docker-compose port mappings to 7150-7153 range (within 7000-7200)
- Add GOPROXY env to Dockerfiles for Go module download in restricted networks
- Verified: all 3 clients connect with 2 peers each, zero decrypt errors

sdk/agent.go

@@ -636,25 +636,17 @@ func isBroadcastMAC(dst []byte) bool {
 }
 
 func deriveKeys(psk, localPub, remotePub []byte) ([32]byte, [32]byte) {
-	var first, second []byte
-	if bytes.Compare(localPub, remotePub) <= 0 {
-		first, second = localPub, remotePub
-	} else {
+	first, second := localPub, remotePub
+	if bytes.Compare(localPub, remotePub) > 0 {
 		first, second = remotePub, localPub
 	}
 	h := sha256.New()
 	h.Write(psk)
 	h.Write(first)
 	h.Write(second)
-	var sendKey [32]byte
-	copy(sendKey[:], h.Sum(nil))
-
-	h2 := sha256.New()
-	h2.Write(sendKey[:])
-	h2.Write([]byte("reverse"))
-	var recvKey [32]byte
-	copy(recvKey[:], h2.Sum(nil))
-	return sendKey, recvKey
+	var key [32]byte
+	copy(key[:], h.Sum(nil))
+	return key, key
 }