- PORT_BASE 20000->30000: team1=31xxx team2=32xxx; syncthing owns 22000
- create_team replaces build: with image: services-<name> so teams reuse base images (was rebuilding 6 images per team, disk 100%)
- recovery: receiver/main.py was corrupted by bad patch (write_file with read_file format); restored from team1 copy + original GitHub
- docker compose -p teamN: project isolation so team compose doesn't overlap (was showing team1 containers for team2)