feat(stdlib): new modules + eslint/tsconfig migration

- Add array/async/etc. modules and type tests; migrate to eslint flat config
  and composite tsconfig (vitest typecheck enabled).
- Fix PubSub.emit to snapshot listeners before iterating (stable EventEmitter
  semantics; avoids invoking listeners added during the same emit).

core/stdlib/src/functions/pipe/index.test.ts

@@ -0,0 +1,34 @@
+import { describe, expect, it } from 'vitest';
+import { pipe } from '.';
+
+describe('pipe', () => {
+  it('apply functions left-to-right', () => {
+    const calc = pipe((n: number) => n + 1, n => n * 2, n => `= ${n}`);
+
+    expect(calc(3)).toBe('= 8');
+  });
+
+  it('pass multiple arguments to the first function', () => {
+    const calc = pipe((a: number, b: number) => a + b, n => n * 10);
+
+    expect(calc(2, 3)).toBe(50);
+  });
+
+  it('support a single function', () => {
+    const inc = pipe((n: number) => n + 1);
+
+    expect(inc(1)).toBe(2);
+  });
+
+  it('preserve this for the first function', () => {
+    const calc = pipe(function (this: { base: number }, n: number) {
+      return this.base + n;
+    }, n => n * 2);
+
+    expect(calc.call({ base: 10 }, 5)).toBe(30);
+  });
+
+  it('return the input unchanged with no functions', () => {
+    expect((pipe as unknown as (...fns: never[]) => (x: number) => number)()(42)).toBe(42);
+  });
+});