Add 30 new tests to handlers_commands_test.go covering previously
untested paths: raviente with semaphore (start, multiplier, ZZ-only
sed/res commands, version gating), course enable/disable/locked/alias,
reload with other players and objects, help filtering for non-op vs op,
ban error paths and long-form duration aliases, and disabled-command
gating for all 12 commands. Total: 62 tests, all passing with -race.
Cover parseChatCommand with 31 tests across all command types:
timer toggle, PSN set/exists, rights, discord token, playtime,
help, ban (permanent/timed/non-op/invalid CID/duration units),
teleport, key quest (version check/get/set), raviente, and
course. Includes mockUserRepoCommands for fine-grained tracking
of command side effects.