refactor(oxlint): enable vitest/consistent-test-it
Enforce `it` over `test` in spec files via
vitest/consistent-test-it (fn: "it"), matching repo convention.
Renamed all 52 pre-existing `test(`/`test.each` usages across
13 spec files to `it(`/`it.each` using oxlint --fix.
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>