systemd --user unit dir on lezama: shared namespace, no collision evidenced, ownership already lives in maintainer registry

~/.config/systemd/user/ on lezama: 28+ unit files (.service/.path/.timer), not git-tracked, no per-agent subdirectory. WHO WRITES: any -cc/-ca agent running as the rob unix user with shell access can drop/edit a unit here - evidenced this session, I created media-dispatch.path/.service/-backstop.timer directly; other units in the same directory (audiobook-compress.*, jirasync-*, media-compress.*, rclone-health.*, context-monitor-drain.*) were authored by other agents/sessions over time (bin-lezama-cc, prior nw-lezama-cc sessions) with no naming registry to check against before creating a new unit. ISOLATION: none formal - convention only (distinct filenames per purpose has avoided a same-file overwrite so far). COLLISION EVIDENCED: none observed - checked systemctl --user list-units + list-timers and ls -la mtimes across the directory, no two units share a name and no unit shows an mtime pattern suggesting concurrent edit. This is a NIL finding for actual collision, evidenced by: directory listing + list-timers/list-units cross-check (the instrument that would show a collision - two agents' independent edits landing on the SAME unit file). NOT exercised: no check of whether two agents have ever raced to enable/daemon-reload at the same moment (would show as a systemd log warning, not checked). EXPOSURE: real but latent - nothing stops two agents choosing the same unit name for different purposes, or one agent editing a unit another agent maintains without a registry lookup first. Maintainer registry (rows 37/38 etc, /var/lib/llmmsg-srv/maintainer-agents.sqlite on venus) is the correct instrument for who owns which unit and IS populated for several of these (I hold rows for media-dispatch, context-monitor-drain, rclone-health-probe, sys-check, memlint-cron) - so the fix, if wanted, is single-ownership via the existing registry, not a new mechanism; not building anything here, flagging only.