21 tests across 6 groups:
A. Config loading & persistence (runtime path, YAML schema, overrides)
B. Runtime state (live globals reading, /config/set sync, restore)
C. Reset (full reset, single-key reset)
D. Server manager (zero-server default, corrupt handling, CRUD, no dead code)
E. GPU deduplication (delegates to config_manager, correct URL switching)
F. Clean imports (no dead os/Union/GUILD_SETTINGS)
Run: ./bot/tests/run_tests.sh (builds + runs in Docker container)