Problem: luals flagged undefined-field on uv timer methods because
race_state.timer was untyped, and undefined-field on env_extra/stdin
because they were missing from the run_scraper opts annotation.
Solution: hoist race_state.timer into a typed local before the nil
check so luals can narrow through it; add env_extra and stdin to the
opts inline type in run_scraper.
Add race.lua with a 1-second vim.uv timer that counts down to a contest
start time and auto-calls setup.setup_contest() at T=0. Exposes
M.start(), M.stop(), and M.status() for command dispatch and statusline
integration.
