Field report: LAN auto-discovery (BT_RELAY=auto) didn't work -- a joiner had to
hand-set BT_RELAY=10.0.0.46:1500 to reach the console every time.
- players/join_lan.bat: BT_RELAY=auto -> BT_RELAY=10.0.0.46:1500 (the operator PC's
LAN IP), with a comment on updating it if the IP changes.
- tools/btoperator.py: the export now DETECTS the operator PC's LAN IP (UDP
default-route probe, no packet sent) and stamps BT_RELAY=<lan-ip>:port into the
generated join_lan.bat instead of "auto" -- so regeneration keeps it correct and
doesn't revert to the broken auto-discovery. Verified: detects 10.0.0.46 here.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
