The paths-filter output in lint-clippy.yml only gated two echo steps;
checkout, toolchain setup and clippy itself ran unconditionally, so
frontend-only PRs still burned a 3-runner matrix on a full clippy build
plus the logging-check tool install.
- lint-clippy/rustfmt/frontend-check: move path filters to workflow
level so irrelevant PRs spawn no runner at all
- split contract-parity into its own workflow; its trigger set spans
both sides and workflow paths cannot vary per job
- clippy paths now cover crates/** and workspace Cargo files, which the
old src-tauri/** filter missed
dev has no required status checks, so path-filtered workflows cannot
get stuck in "Expected".