Serve the BotFather game noitu from the bot's HTTP server under
/games/noitu when GAME_BASE_URL is set. /noitu sends the game, Play
answers with a signed, expiring link, and the server validates every
word against the embedded noitu dictionary (CC BY-SA 4.0), runs the
bot opponent and turn timer, and reports the score with setGameScore.
Modules can now register game-short-name callbacks and HTTP routes.
Implements Phases 02 (partial) and 03 of the go-port-cloud-run plan.
Introduces module framework with per-module KV prefix isolation,
health check endpoint, request timeout protection, and comprehensive
test coverage. Cloud Run deployment deferred to Phase 01.
Security hardening: constant-time secret comparison, cron auth bridge,
and secrets stripped from dependency environment exports. Includes
Dockerfile, GitHub CI workflow (vet + race + build), and integration
tests for module lifecycle.