Adds the **Public repo hygiene** policy to AGENTS.md, matching what starfleet/roster and communicator-esp32/computer now use:
- The Forgejo repo is public — never commit internal hostnames, LAN IPs, usernames, home paths, or credentials.
- Phone credentials stay in the local, gitignored `.env`; tracked files use `<device-ip>` placeholders.
- Includes a pre-push scan command for private addresses/identifiers (excluding vendored websockets).
No functional changes.
Co-authored-by: Troed Sångberg <github@troed.se>
Reviewed-on: #1
troed
f45ae8e07f