Better error cards for private messages, neighbor info rendering

decoder/decoder.go

@@ -308,7 +308,12 @@ func decodeEncryptedPayload(data *meshtreampb.Data, encrypted []byte, channelId
 				TextMessage: string(decrypted),
 			}
 		} else {
-			data.DecodeError = fmt.Sprintf("failed to parse decrypted data: %v", err)
+			// Check if this channel is configured - if not, likely a private message
+			if !IsChannelConfigured(channelId) {
+				data.DecodeError = fmt.Sprintf("PRIVATE_CHANNEL: failed to parse decrypted data on unconfigured channel '%s': %v", channelId, err)
+			} else {
+				data.DecodeError = fmt.Sprintf("PARSE_ERROR: failed to parse decrypted data: %v", err)
+			}
 			data.Payload = &meshtreampb.Data_BinaryData{
 				BinaryData: decrypted,
 			}

decoder/keys.go

@@ -72,6 +72,15 @@ func RemoveChannelKey(channelId string) {
 	delete(channelKeys, channelId)
 }
 
+// IsChannelConfigured checks if a channel has a specific key configured
+func IsChannelConfigured(channelId string) bool {
+	channelKeysMutex.RLock()
+	defer channelKeysMutex.RUnlock()
+
+	_, ok := channelKeys[channelId]
+	return ok
+}
+
 // PadKey ensures the key is properly padded to be a valid AES key length (16, 24, or 32 bytes)
 func PadKey(key []byte) []byte {
 	// If key length is already valid, return as is