Add FuzzParseBytes and FuzzSanitizeYAMLEscapes in internal/model/fuzz_test.go.
Both targets run as regular seed-based tests in CI (go test ./...) and can be
run continuously via `task fuzz` (default 30 s per target; FUZZ_TIME=60s to
extend). Fuzz corpus failures are saved to testdata/fuzz/ for regression.
Add cliff.toml configuring git-cliff to generate Keep-a-Changelog-compatible
release notes from Conventional Commits. New tasks: `task changelog`
(regenerate full CHANGELOG.md) and `task changelog-next` (preview unreleased
entries without writing). Requires git-cliff (brew/cargo install git-cliff).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>