Constant CLAUDE_MD_OWNERSHIP_MARKER_PATH 

const CLAUDE_MD_OWNERSHIP_MARKER_PATH: &str = ".claude/.agentmux-claude-md-ownership.json";

One-time marker recording whether the @import line (below) has already been offered for this working directory. Checked INSTEAD of re-scanning CLAUDE.md content on every launch — without it, a user who deliberately deletes the import line (opting out of AgentMux content entirely) would see it silently reappear on their next launch.