CampaignListener cleared its input and speaker at turn start but never its narration, so every delta appended to one buffer for the whole session and each done wrote the whole running history to the transcript. Every turn re-appended every earlier turn's narration, so a multi-turn session grew the transcript unboundedly and drowned the player's own lines in a full copy of the conversation. turn_start now clears the narration buffer the way the scanner clears its own, and a two-turn test guards it.