This branch replaces Projen with mise as the primary way to run installs, builds, linting, docs, and security tasks, and reorganizes the repo into a clearer monorepo layout with a single Yarn lockfile at the root.

Motivation

• Drop generated Projen config (.projen/, .projenrc.ts, per-package Projen manifests) in favor of explicit, version-controlled mise.toml files and small shell helpers.
• Put the CDK app in cdk/ so infrastructure, CLI, and docs are clearly separated workspaces under one yarn install.
• Align CI and contributor docs with mise run install / mise run build (and optional mise run quality / mise run security).