Tests previously ran on Ubuntu only, so Windows- and macOS-specific breakage went unseen. Add a 3-OS test matrix and a separate lint job for rustfmt and clippy. Lint is continue-on-error because the tree is not yet fmt-clean or clippy-clean.
Also add BEDIT characterization tests that pin current session, undo and refusal behavior ahead of the editor refactor. Locked tests guard behavior that must survive; documenting tests record questionable behavior expected to change.
- .github/workflows/ci.yml runs `cargo test --workspace --locked` on
pushes to main and on pull requests, with the Linux libraries the
release build installs. No formatter check: the tree is not
rustfmt-clean and stays that way.
- flake.nix, flake.lock and the direnv hook are removed. Nothing used
them, and their pinned dependency hashes were already stale after the
codec and kernel bumps.
- Under cfg(test) the "system" language resolves to en-US. The unit
tests compare English text through one process-wide loader, and every
apply_config of a default config asked for the system language, so a
Turkish locale failed 22 tests and parallel tests raced each other
through a language switch (the thickness-row test found its section
under one language and looked it up under another).
- The arc grip test follows #1352: the start, end and midpoint grips
drive the whole arc.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>