How do I install PowerPack?

The canonical install instructions are PR#2 on this repo: #2

Three paths (pick one):
• Option A — Xcode quick install (no L&L customizations)
• Option B — Xcode + L&L customizations (interactive installer walks you through it)
• Option C — Browser build (no Mac required)

If you hit an issue not covered there, reply below with: which option you used, the full installer output, and the Xcode build error if applicable.