Merge-time fix for #660. CLAUDE.md and architecture-invariants still said a
raw npx vitest skips setup.ts, contradicting the updated Testing note: both
now say it resolves the root vitest.config.ts (and why that file must stay).
The architecture-invariants entry for safeRmHomeTree adds the sandbox-HOME
requirement (isSandboxedHome, TEST_HOME_PREFIX), the same rule for
isUnderTestHome, the route-harness assert and the 2026-10-10 incident.
CLAUDE.md's repo-root preamble lists vitest.config.ts with its reason, so a
tidy-up does not move it into config/ and reopen#640. The
assertSandboxedHome JSDoc no longer claims every route test is covered: only
the ones built on createRouteTestHarness are.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>