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/compose/index.test-d.ts

@@ -0,0 +1,18 @@
+import { describe, expectTypeOf, it } from 'vitest';
+import { compose } from '.';
+
+describe('compose', () => {
+  it('infers the final return type through the chain', () => {
+    const fn = compose((s: string) => s.length > 0, (n: number) => `${n}`, (n: number) => n + 1);
+
+    expectTypeOf(fn).parameters.toEqualTypeOf<[number]>();
+    expectTypeOf(fn).returns.toEqualTypeOf<boolean>();
+  });
+
+  it('keeps the variadic parameters of the last function', () => {
+    const fn = compose((n: number) => `${n}`, (a: number, b: number) => a + b);
+
+    expectTypeOf(fn).parameters.toEqualTypeOf<[number, number]>();
+    expectTypeOf(fn).returns.toEqualTypeOf<string>();
+  });
+});