PGlite's WASM worker kept an open async handle, causing Bun to detect
a resource leak and exit with code 100 despite all tests passing.
Adds a preload script that closes the cached client via afterAll.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Prevents bare `bun test` from picking up Playwright .spec.ts files
in the e2e/ directory.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>