## Problem
After the initial submit hardening, two issues remained: source code was
read in Lua and piped as stdin to the scraper (unnecessary roundtrip
since
the file exists on disk), and CF's `page.fill()` timed out on the hidden
`textarea[name="source"]` because CodeMirror owns the editor state.
## Solution
Pass the source file path as a CLI arg instead — AtCoder calls
`page.set_input_files(file_path)` directly, CF reads it with
`Path(file_path).read_text()`. Fix CF source injection via
`page.evaluate()`
into the CodeMirror instance. Extract `BROWSER_SUBMIT_NAV_TIMEOUT` as a
per-platform `defaultdict` (CF defaults to 2× nav timeout). Save the
buffer
with `vim.cmd.update()` before submitting.
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.
