feat(stdlib): add immutable array ops, deep set, and isEqual comparator

Adds arrays/{move,insert,swap,remove}, collections/set, and comparators/isEqual (NaN/Date/RegExp/Map/Set/cycle-safe), wired into the barrels.

core/stdlib/src/arrays/move/index.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it } from 'vitest';
+import { move } from '.';
+
+describe('move', () => {
+  it('move an item forward', () => {
+    expect(move(['a', 'b', 'c'], 0, 2)).toEqual(['b', 'c', 'a']);
+  });
+
+  it('move an item backward', () => {
+    expect(move(['a', 'b', 'c'], 2, 0)).toEqual(['c', 'a', 'b']);
+  });
+
+  it('clamp the target index', () => {
+    expect(move(['a', 'b', 'c'], 0, 99)).toEqual(['b', 'c', 'a']);
+  });
+
+  it('return a copy unchanged for an out-of-range source', () => {
+    const source = ['a', 'b'];
+    const result = move(source, 5, 0);
+    expect(result).toEqual(['a', 'b']);
+    expect(result).not.toBe(source);
+  });
+
+  it('never mutate the source', () => {
+    const source = ['a', 'b', 'c'];
+    move(source, 0, 2);
+    expect(source).toEqual(['a', 'b', 'c']);
+  });
+});