Self-hosted NAT hole-punching relay for Dolphin emulator netplay.
Enables online play for ALL GameCube and Wii games without players
needing to open ports (Mario Party 4-7, MKDD, Smash Melee, etc).
Multi-stage Docker build compiles only the traversal_server target.
UDP ports 6262 (primary) and 6226 (NAT probe).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>