The build-exe and build-exe-cross suites invoke `bun build` in beforeAll
hooks and pegged CPU for ~6 min on every test run (one cached-on-miss
build plus three unconditional cross-target builds). Move them to a
dedicated vitest project, skip them unless CI=1 or FUSION_TEST_BUILD_EXE=1
is set, and add cache guards so CI re-runs skip rebuilds when the target
binary already exists. With build-exe out of the default cli run, the
main config can enable fileParallelism.
Run on demand via `pnpm --filter @runfusion/fusion test:build-exe`.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
