refactor(runtime): collapse unused setup layers

.agents/notes/implemented/architecture/2026-07-28-portable-execution-world-consumers.md

@@ -23,7 +23,7 @@ Generic consumers use that execution world:
 - `dsh-bash-local` continues to map Bash semantics onto ordinary `ctx.subprocess.spawn()`.
 - `dsh-lsp-local` reads and contains source through `ctx.fs`, resolves and launches language servers through `ctx.subprocess`, and carries provider-owned file URIs through initialization and result rendering. One provider-lifetime signal aborts filesystem and protocol work during disposal, including workspace lookup before queue ownership; its JSON-RPC, pooling, synchronization, and normalization stay unchanged.
 - `dsh-pty-local` maps persistent-shell semantics onto `ctx.subprocess.spawnTerminal()`. The local `node-pty` and process-inspection implementation moves into `dsh-subprocess-local`; another subprocess provider supplies the same primitive. `danger-full-access` needs no `ctx.sandbox`; a confined mode requires a same-world sandbox provider and fails before spawn when none is mounted. Prompt and silence evidence collected during asynchronous pre-write inspection is discarded when the provider write begins. Cancellation retains the send reservation while an in-flight write settles and then signals the foreground group, so late bytes or the signal cannot target a successor; an in-flight readiness poll cannot release that reservation, and a rejected write sends no signal. The absolute deadline remains armed throughout cancellation. A signal failure becomes terminal transport failure. Completion of a stale inspection resumes polling for the current send. Startup cancellation begins terminal rollback without waiting for a stalled readiness or signalling call. Close rejects new public signals and delegates provider-observable session quiescence to the handle's awaited termination operation.
-- `dsh-code-runtime-subprocess` materializes a dependency-free runner through `ctx.fs` and launches it through `ctx.subprocess`, preserving the Code Runtime binding and output contract across local or remote worlds. The fixed runner is adapter-owned infrastructure below `ctx.subprocess.runtimeRoot`, so its write carries an explicit `danger-full-access` policy instead of inheriting the model-facing filesystem mode. It shares host-side worker mechanics through the non-plugin `dsh-code-runtime-worker/runtime-host` subpath instead of copying them. Preparation carries one lifecycle signal through filesystem resolution, materialization, and executable lookup so disposal can abort a stalled provider. The heap-bounded worker rejects oversized binding frames before transfer, each outer hop enforces the same bound before forwarding, and raw subprocess pipes carry newline-delimited UTF-8 JSON without a redundant base64 representation. The launcher publishes an accepted terminal frame before reaping its controller so a descendant that inherits controller pipes cannot suppress completion; the host still awaits process-group quiescence.
+- `dsh-code-runtime-subprocess` passes a bundled dependency-free eval runner directly to `ctx.subprocess`, preserving the Code Runtime binding and output contract across local or remote process worlds without a filesystem dependency or provider-specific package. It shares host-side worker mechanics through the non-plugin `dsh-code-runtime-worker/runtime-host` subpath instead of copying them. The heap-bounded worker rejects oversized binding frames before transfer, each outer hop enforces the same bound before forwarding, and raw subprocess pipes carry newline-delimited UTF-8 JSON without a redundant base64 representation. The launcher publishes an accepted terminal frame before reaping its controller so a descendant that inherits controller pipes cannot suppress completion; the host still awaits process-group quiescence.
 
 `dsh-code-runtime-worker` remains a separate implementation. It is the smaller in-process backend and works in single-file distributions that cannot assume an installed Node executable. Remote filesystem/process compositions select `dsh-code-runtime-subprocess`; they do not need a provider-specific Code Runtime package.
 
@@ -39,7 +39,7 @@ Generic consumers use that execution world:
 
 **Add a stable bounded-read primitive to the filesystem seam.** Rejected because only LSP needs a complete-document byte ceiling, which it can enforce while consuming the existing text stream. A second primitive forces every provider to implement stable-handle and no-follow mechanics, including a remote helper protocol, without an observed concurrent-replacement defect.
 
-**Delete the worker-thread Code Runtime.** Rejected because portability does not erase its current deployment need. The subprocess backend requires a Node executable and filesystem materialization; the worker backend has neither requirement and remains the supported single-process path.
+**Delete the worker-thread Code Runtime.** Rejected because portability does not erase its current deployment need. The subprocess backend requires a Node executable; the worker backend does not and remains the supported single-process path.
 
 **Run the whole harness inside the remote environment.** Rejected as a different deployment model. Making execution capabilities portable does not move model calls, session state, plugin state, or the agent loop.