Project init — bootstrap agent workflow

Only when the user invokes /init or asks to initialize this repo — never automatic.

Sets up Superpowers + Faruk mandatory skills in the current project. Does not scaffold apps, commit, or push.

Summary (what init does)

#	Action
1	Create `docs/superpowers/specs/` and `plans/` (+ README)
2	Install mandatory skills at project scope
3	Ensure `/commit-push`, `/init`, and `/recap` in `.cursor/commands/`
4	Optional: Cursor rules + `docs/release-history.json` for web apps
5	Merge AGENTS.md workflow table (never replace a rich file)