roundstorm: the test suite stops opening the real database and running real brains

A Dependabot pull request that failed one Ubuntu cell with “database is locked” was not the bump’s fault. Importing nearly anything under server/src imports db.ts, which opens a SQLite file at import, and ten test files never set ROUNDSTORM_DATA first — so they opened the default data directory, the real database on a developer’s machine, and on CI one file shared by every parallel test process racing to create and migrate it (44a5bd9). A second bug surfaced in the same empty-HOME experiment: gate.test.ts called /api/bootstrap, which probes every brain, so npm test executed the real agy and cursor-agent CLIs on any machine that had them. scripts/test-setup.mjs is now preloaded into every test process and hands each its own empty data directory rather than relying on the next author to remember, gate.test.ts hits /api/memory instead, and a re-run under an empty HOME passes 196 of 196 while creating nothing there.