--check refreshes the cache, merges the local overlay, and compares the
deterministic rendering with tracked typos.toml, exiting non-zero on drift
without rewriting the tracked file. It is a local inspection tool, useful when
reviewing whether an overlay change alters the rendered output.
Because the authority is live, a tracked typos.toml drifts whenever the
shared dictionary changes, so continuous integration (CI) must not run
--check against a tracked typos.toml: that would fail every consumer's
build on every shared dictionary edit. Use gate, which always writes the
current rendering before checking it with Typos and the phrase check, for the
CI-facing spelling gate.