Phase A epic ([KPR-210](https://linear.app/keepur/issue/KPR-210)) closeout.
Sunsets internal agent runtime; positions hive as the orchestration/governance/channel layer above the Claude Agent SDK. Per-turn `query()` with session resume is the only execution path. AgentManager simplifies to a spawn coordinator. Skills layout flattens. Prompt prefix cache + spawn coordinator heartbeats land in `db.telemetry`.
Full epic detail in PR #266 (squash-merged at eb064c63).
Co-authored-by: Mokie Huang <mokie.huang@gmail.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>