note: Queue routing checked after Dashboard Queue. FS store feature depends on worker-runtime core `00001KVZBCQH4`, which is currently inprogress and under review. Do not start FS persistence implementation until core API is reviewed/merged/done.

author: yoi-orchestrator


note: `00001KVZBCQH4` が done になり dependency blocker 解消。Backend Registry foundation Ticket とは主対象が `crates/worker-runtime` vs `crates/workspace-server` で分離できるため並行受理候補。ただし Cargo/package lock conflict は merge時に Orchestrator が解消する。

summary: worker-runtime core done 後の optional `fs-store` feature slice。core no-default-features を維持しつつ FS persistence backend、layout、atomic writes、bounded reads、corrupt diagnostics、memory/FS tests を追加する。REST/Backend integration は扱わない。

role_plan: Orchestrator が dedicated child worktree を作成し、coder Worker に `crates/worker-runtime` と lock/package files の write scope を委譲する。reviewer Worker は read-only で feature gating、atomic/corrupt diagnostics、runtime_id+worker_id authority、no standalone worker-store を確認する。merge/validation/done/cleanup は Orchestrator が行う。