feat!: bump to v2 - require Node.js >= 20, upgrade all dependencies (#67)

BREAKING CHANGE: Minimum Node.js version raised from 16 to 20 LTS.

- Migrate from deprecated @aws-sdk/hash-node, @aws-sdk/protocol-http,
  @aws-sdk/signature-v4, @aws-sdk/types to @smithy/* equivalents
- Upgrade TypeScript 5.2 → 6.0, target/lib es2022 → es2024
- Upgrade moduleResolution from "node" (deprecated in TS6) to "bundler"
- Upgrade Jest 29 → 30, projen 0.79 → 0.99, ESLint 8 → 9,
  @typescript-eslint 6 → 8, prettier-plugin-organize-imports 3 → 4
- Fix previously-skipped TimeoutError test by isolating socket timeout
  from AbortSignal race condition
- Fix IAM auth test for new credential-provider-node behavior that
  prefers AWS_PROFILE over explicit env vars
- Replace deprecated Jest matcher toBeCalledTimes → toHaveBeenCalledTimes

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: tinovyatkin