test(hygiene): close two more brains found by a broadened rescan

A second, structural pass of the honest scan (any local helper that
constructs a Brainy directly, not just ones named like openBrain/makeBrain,
plus support for new Brainy<T>(...) generics) surfaced two more real leaks
outside the first 93-file list: writer-lock-fencing.test.ts's `second`
(a rejected-init() brain never pushed into the file's own tracked array)
and plugin-version-coupling.test.ts's last case (a rejected-init() brain
with no close at all).

tests/unit/plugin-version-coupling.test.ts

@@ -143,5 +143,6 @@ describe('version coupling at init() — no silent fallback', () => {
       plugins: ['@soulcraft/this-package-does-not-exist-xyz']
     })
     await expect(brain.init()).rejects.toThrow(/could not be loaded|config\.plugins/)
+    await brain.close().catch(() => {})
   })
 })