Port 5050 binds to 127.0.0.1 inside container, unreachable externally.
Port 9080 (nginx) proxies /v2/ correctly and returns 401 as expected.
Combined with network_mode=host runner, all traffic stays on LAN.
Use internal registry at 10.10.10.10:5050 instead of git.daddelolymp.de
which routes through Pangolin proxy over internet (40Mbit bottleneck).
All layer cache pulls/pushes and image pushes now stay on LAN.
These flags caused build time regression from ~2:48 to 6:30.
snapshot-mode=redo does full filesystem walks per layer (slowest mode).
Default time-based mode is much faster for CI builds.