v2.0.0 — user-global install model

Breaking: the six skills now install user-global; install.sh/install.ps1 are removed and AGENT-INSTALL.md is the only install path.

• Skills copy to per-user global skill directories (~/.agents/skills/, ~/.claude/skills/, ~/.gemini/config/skills/, ~/.cline/skills/); nothing is written into projects — no bridges, no .gitignore edits.
• The only per-project footprint is the generated agent tests themselves (*.agentic.spec.*, …), which are committed — they are the safety net.
• Cursor supported: discovers the ~/.agents/skills/ copies natively.

Migration from v1 project-scoped installs: re-run the install prompt once per user; stale gitignored project adapters can be removed manually.