Migrate to pnpm

[julianschiller]

Closes #

Migrate the monorepo from npm workspaces to pnpm for faster installs. Turborepo (tasks) and Changesets (publishing) are unchanged — only the package manager was swapped.

Changelog

New

• pnpm-workspace.yaml — workspace globs plus pnpm settings (nodeLinker: hoisted, linkWorkspacePackages: true, allowBuilds for esbuild/@parcel/watcher, and overrides)
• pnpm-lock.yaml
• CI now uses pnpm/action-setup + actions/setup-node with cache: 'pnpm' (pnpm store caching)

Changed

• packageManager set to pnpm@11.15.1; workspace globs moved from package.json to pnpm-workspace.yaml
• Both workflows: npm ci → pnpm install --frozen-lockfile, scripts run via pnpm run
• update:lock → pnpm install --lockfile-only
• @types/node pinned to ^20 via overrides (26.x is too new for TypeScript 5.4.5)
• clean-architecture and form-vue rebuilt with the tsc → Rollup pattern (like the other 8 packages), since rollup-plugin-typescript2 no longer transforms under pnpm

Removed

• package-lock.json (replaced by pnpm-lock.yaml)
• The update:registry lockfile-rewrite hack (root + per-package scripts + CI steps) — pnpm's lockfile is registry-neutral
• resolutions field from package.json (moved to overrides in pnpm-workspace.yaml)
• rollup-plugin-typescript2 / -vue / -clear from clean-architecture and form-vue