Drives all infra src files to 100% (env.ts, db/client.ts, db/ensure-dir.ts,
db/migrate.ts, db/seed.ts, routes/health.ts).
- env.test.ts: dev defaults when unset, overrides when set (PORT coerced),
CORS_ORIGINS parsing (trim + drop empties) and empty-fallback.
- db.test.ts: runMigrations idempotency; ensureDbDir no-op for non-file URLs
and bare filenames (branch coverage).
- seed.test.ts: production guard — no dev users seeded when NODE_ENV=production.
- c8-ignore the migrate.ts/seed.ts CLI direct-run blocks (unreachable under vitest).
No lifecycle test (infra domain, per plan). No bugs found — infra code correct;
only coverage gaps. All 112 API tests green; typecheck + oxlint clean.
