Refactor ensureDir to remove redundant existence check

- Remove explicit `fs.existsSync` check in `ensureDir`.
- Rely on `fs.mkdirSync(dir, { recursive: true })` idempotency.
- Verified with existing tests in `test/ops.test.mjs`.

Co-authored-by: PR0M3TH3AN <[email protected]>

src/ops.mjs

@@ -29,9 +29,7 @@ function getPaths(userRoot) {
 }
 
 function ensureDir(dir) {
-  if (!fs.existsSync(dir)) {
-    fs.mkdirSync(dir, { recursive: true });
-  }
+  fs.mkdirSync(dir, { recursive: true });
 }
 
 function transformContent(content) {