Strengthen Clone Interview goal-to-plan flow

[Turtle-Hwan]

Summary

• Strengthen /clone:interview from a requirements ledger into a goal-to-plan interview with Goal Contract, Decision Ledger, Plan Draft, Readiness Audit, and Execution Handoff.
• Split reusable data/calculation concerns into shared modules for paths, utilities, display formatting, MCP client metadata/RPC, plugin version, and interview answer matching.
• Remove hardcoded MCP client versions and release-time hook rewrites; plugin manifests are now the version source of truth.
• Replace shell-specific loop cancellation with a Node cancel script and test coverage.

Verification

• pnpm test (67 tests)
• claude plugin validate .
• git diff --check