Each plugin package invokes `tsc` in its build script but previously relied on
a root-hoisted typescript. When the root symlink breaks (e.g. after switching
worktrees that shared a pnpm store), `pnpm -r build` fails with MODULE_NOT_FOUND
for tsc — blocking `pnpm dev dashboard`. Declaring typescript locally makes
each plugin self-sufficient.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>