Co-locate update-package-hashes.sh helper script to wrap nurl and
show recent releases. Simplify SKILL.md documentation. Bump
pi-coding-agent from 0.70.0 to 0.70.2 with updated hashes.
- Added pi-coding-agent package definition with buildNpmPackage
- Includes npm dependencies and native/build inputs for GUI libraries
- Skips generate-models step during build (models already in repo)
- Creates 'pi' executable pointing to coding-agent dist/cli.js
Fixes build issues where generate-models would fail during build phase