Attempt to create a test

As requested, currently failing: ```sh theodores-MacBook-Pro:zenfs-core theodorebrockman$ npx tsx tests/backend/single-buffer.test.ts ▶ SingleBuffer ✔ filesystem restoration from original buffer (with same metadata) (10.657334ms) ✔ cross-thread SharedArrayBuffer (99.360167ms) ✖ should recursively copy files with with same stats (28.865125ms) ✖ SingleBuffer (139.574667ms) ℹ tests 3 ℹ suites 1 ℹ pass 2 ℹ fail 1 ℹ cancelled 0 ℹ skipped 0 ℹ todo 0 ℹ duration_ms 1017.996416 ✖ failing tests: test at tests/backend/single-buffer.test.ts:1:1499 ✖ should recursively copy files with with same stats (28.865125ms) Exception [Error]: EISDIR: File is a directory, open '/dst' at Module._openSync (file:///Users/theodorebrockman/Documents/dev/zenfs-core/dist/vfs/sync.js:227:15) at Module.openSync (file:///Users/theodorebrockman/Documents/dev/zenfs-core/dist/vfs/sync.js:238:27) at Module.utimesSync (file:///Users/theodorebrockman/Documents/dev/zenfs-core/dist/vfs/sync.js:623:25) at Module.cpSync (file:///Users/theodorebrockman/Documents/dev/zenfs-core/dist/vfs/sync.js:850:20) at TestContext.<anonymous> (/Users/theodorebrockman/Documents/dev/zenfs-core/tests/backend/single-buffer.test.ts:66:6) at process.processTicksAndRejections (node:internal/process/task_queues:105:5) at async Test.run (node:internal/test_runner/test:1054:7) at async Suite.processPendingSubtests (node:internal/test_runner/test:744:7) { errno: 21, code: 'EISDIR', path: '/dst', dest: undefined, syscall: 'open' } ```