Move the Darwin Breeze Dark color scheme and global theme into a stow
package. build.py generates the Helium, T3 Code and Ghostty themes from
DarwinBreezeDark.colors, and apply.sh rebuilds and applies them, so the
colors are edited in one place.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Install the pnpm native binary from GitHub releases via gh-r and sbin,
matching the existing fnm/starship shim pattern. Node is now managed
by pnpm itself (pnpm runtime), so fnm and its init block are removed.
Drop unzip from the README optional list; only fnm's zip needed it.