chore: establish learning module baseline

OpenMAIC/eval/shared/run-dir.ts

@@ -0,0 +1,16 @@
+import { mkdirSync } from 'fs';
+import { join } from 'path';
+
+/**
+ * Build and create a run directory under `<baseDir>/<sanitized-model>/<timestamp>/`.
+ * The model string is sanitized by replacing `:` and `/` with `-` so it is
+ * safe to use as a directory name. Timestamp is ISO-8601 with colons and dots
+ * replaced by dashes, truncated to second precision.
+ */
+export function createRunDir(baseDir: string, model: string): string {
+  const sanitizedModel = model.replace(/[:/]/g, '-');
+  const timestamp = new Date().toISOString().replace(/[:.]/g, '-').slice(0, 19);
+  const runDir = join(baseDir, sanitizedModel, timestamp);
+  mkdirSync(runDir, { recursive: true });
+  return runDir;
+}