Groups the pi Agent lifecycle, factory, signature contract, and env/redaction helpers into src/main/worker/runtime/. WorkerRunner is the module's public entry and lives in runtime/index.ts; pi-agent-factory and pi-hook-contract stay named for their role as visible runtime boundaries; helpers.ts carries ParentMessage/ChildMessage/RunJob types plus redactor + env override utilities. entry/index.ts and agent-runtime/runtime-message-injector.ts updated to import from the new paths.