Chat SDK adapters use prefixed platform IDs (e.g. "telegram:6037840640", "discord:guildId:channelId") but users provide raw IDs during setup. Without the prefix, the router can't match the registered messaging group to incoming messages and silently drops them. register.ts now auto-prefixes with the channel type if not already present. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>