Reconcile Design Patterns successor package

[ryanhelms]

Summary

• reconcile the legacy Design Patterns plugin into its standalone authority
• add deterministic four-provider release staging and package contracts
• preserve internal Claude commit versioning and add Codex, Grok, and Kimi projections
• add legal, source-inventory, provider-validation, and release-contract coverage
• fail closed in CI until marketplace-server trusted-publisher OIDC exchange exists

Verification

• root tests: 20/20
• packaged tests: 35/35
• golden evals: 6/6 in both source and staged package
• exact marketplace-server validation: Claude, Codex, Grok, and Kimi
• deterministic 356-file staging digest: sha256:833265e1beeb60a97b933f34389d140f21acc8ac1d2743dc2af7d3c0da817a77

Publication is intentionally blocked; this PR does not activate, sign, or retire the legacy marketplace.