Add initial project files

packages/utils/src/array/arrayDedup.ts

@@ -0,0 +1,36 @@
+type Value = string | number | boolean | null | undefined | Value[] | { [key: string]: Value };
+
+export function arrayDedup<T extends Value>(arr: T[]): T[] {
+  const seen = new Map<string, T>();
+
+  for (const item of arr) {
+    const key = stableStringify(item);
+    if (!seen.has(key)) {
+      seen.set(key, item);
+    }
+  }
+
+  return Array.from(seen.values());
+}
+
+/**
+ * Deterministic stringify:
+ * - sorts object keys
+ * - preserves arrays order
+ * - distinguishes undefined/null
+ */
+function stableStringify(value: Value): string {
+  if (value === undefined) return 'undefined';
+  if (value === null) return 'null';
+
+  if (Array.isArray(value)) {
+    return `[${value.map(stableStringify).join(',')}]`;
+  }
+
+  if (typeof value === 'object') {
+    const keys = Object.keys(value).sort();
+    return `{${keys.map((k) => `${k}:${stableStringify(value[k])}`).join(',')}}`;
+  }
+
+  return `${typeof value}:${String(value)}`;
+}