Adds the skills:admin router (cloud/sdk/skill_api.py) for cloud-skill CRUD and per-host entitlement grant/revoke with CSRF/scope/audit, and a host-scoped router serving incremental per-host sync deltas plus the agent local-skill inventory report/readback. Both composed into the Cloud API app. cloud-api suite green (46 passed). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>