feat: add receipt-gated React planning suite

[AlexU-A]

Summary

• add framework-routed React planner and receipt-gated executor
• replace raw external-skill loading with a verified v2 lock and runtime resolver
• migrate React, Next.js, React Native, and proposal critic routing to pinned bundles
• add CI, scheduled freshness checks, research, agent-eval harness, and Claude handoff

Verification

• 37 merged unit tests passed; 87% measured coverage
• offline lock/lineage validation passed for 45 identities and 521 files
• live content verification passed for all 45 identities
• freshness check passed for 31 active entries after a focused one-pin refresh
• actionlint, py_compile, resolver doctor, and diff/secret checks passed

Boundary

Real Claude CLI behavioral evaluation remains UNVERIFIED because the recorded executor run hit the authentication-source blocker and the planner run timed out. This PR does not claim deployment or model-behavior acceptance.