feat: route backend worker controls over protocol

.yoi/tickets/00001KY1ZKCPC/item.md

@@ -2,7 +2,7 @@
 title: 'Backend runtime経由の操作をprotocol transportへ統一しTUI同等にする'
 state: 'planning'
 created_at: '2026-07-21T09:20:07Z'
-updated_at: '2026-07-21T09:47:10Z'
+updated_at: '2026-07-21T10:33:12Z'
 assignee: null
 readiness: 'draft'
 ---

.yoi/tickets/00001KY1ZKCPC/thread.md

@@ -21,3 +21,77 @@ Ticket item updated: title, body.
 Ticket item updated: title, body.
 
 ---
+
+<!-- event: plan author: assistant at: 2026-07-21T09:55:56Z -->
+
+## Plan
+
+Implementation started.
+
+Plan for this pass:
+- Inspect local Worker protocol transport and current Backend/frontend HTTP operation mappings.
+- Add a Backend/runtime protocol command transport that accepts existing `protocol::Method` payloads rather than per-operation HTTP endpoints.
+- Route TUI Backend Runtime client through that protocol transport for run/notify/completion/cancel/pause/resume/compact/rewind operations.
+- Route browser Console operations through the same protocol transport and stop using HTTP operation endpoints as the normal path.
+- Keep existing HTTP endpoints only as compatibility where needed, not as frontend/TUI authority.
+
+---
+
+<!-- event: implementation_report author: assistant at: 2026-07-21T10:33:12Z -->
+
+## Implementation report
+
+Implementation update:
+
+Implemented the first full protocol-transport pass for Backend/runtime Worker controls.
+
+Backend/runtime:
+- Added `Runtime::send_protocol_method(...)` in `worker-runtime`.
+  - `Method::ListCompletions` returns direct `Event::Completions` for same-command-connection semantics.
+  - Other methods are delivered unchanged to the execution backend.
+- Added `WorkerExecutionBackend::dispatch_method(...)` and concrete support in `WorkerRuntimeExecutionBackend`.
+  - This accepts existing `protocol::Method` values instead of translating through operation-specific HTTP request DTOs.
+- Added runtime command WebSocket:
+  - `/v1/workers/{worker_id}/protocol/ws`
+  - accepts raw `protocol::Method` JSON frames
+  - returns raw direct `protocol::Event` JSON frames where needed
+- Added workspace-server command WebSocket:
+  - `/api/runtimes/{runtime_id}/workers/{worker_id}/protocol/ws`
+  - `/api/w/{workspace_id}/runtimes/{runtime_id}/workers/{worker_id}/protocol/ws`
+- Added `RuntimeRegistry::send_protocol_method(...)` and embedded runtime forwarding.
+
+TUI client:
+- Reworked `BackendRuntimeClient` so `send(&Method)` no longer maps to HTTP `/input`, lifecycle, or unsupported diagnostics.
+- It now opens a command WS to `/protocol/ws` and sends cloned raw `protocol::Method` values.
+- Direct command response events are merged into the existing event queue alongside observation WS events.
+- This removes the previous unsupported handling for pause/resume/compact/completions/rewind at the TUI client transport layer.
+
+Browser Console:
+- Added command WS connection to `/protocol/ws` while keeping `/events/ws` as observation stream.
+- Removed normal operation use of HTTP `POST /input` and `POST /completions` from the Console page.
+- Composer send now maps to protocol methods:
+  - user input -> `Method::Run` with protocol `Segment[]`
+  - system input -> `Method::Notify { auto_run: true }`
+  - `:compact` -> `Method::Compact`
+  - `:rewind` -> `Method::ListRewindTargets`
+  - `:peer` -> `Method::RegisterPeer`
+- Completion lookup now sends `Method::ListCompletions` over command WS and waits for direct `Event::Completions`.
+- Added frontend controls for cancel / pause / resume / compact / rewind target request / rewind to target.
+
+Compatibility note:
+- Existing HTTP operation endpoints remain in backend/server as compatibility for now, but the TUI Backend client and browser Console normal path now use protocol transport.
+
+Verification run under `nix develop`:
+- `cargo fmt -- --check`
+- `cargo check -p worker-runtime -p yoi-workspace-server -p client -p tui`
+- `cargo test -p client backend_runtime --lib`
+- `cargo test -p yoi-workspace-server registry_worker_list_can_be_scoped_by_runtime_id --lib`
+- `cargo test -p worker-runtime --features ws-server --lib worker_backend`
+- `git diff --check`
+
+Frontend check note:
+- `web/workspace/package.json` currently has no check script and local frontend dependencies are not installed in this worktree.
+- Attempted temporary `npm exec --package svelte-check --package typescript -- svelte-check`, but the tool bootstrap failed before checking project code.
+- The Svelte page was updated against the generated protocol types in `web/workspace/src/lib/generated/protocol.ts`, but a frontend-native check still needs to be run in an environment with the frontend deps installed.
+
+---