fix(pkg): support worker-backed tools in single exe

pkg stores application files in a virtual filesystem, and its
worker_threads hook discovers worker entry points only when they are passed
as filesystem strings. Convert the code-runtime entry with fileURLToPath()
and return the workflow built entry as a string while retaining its
source-mode data URL bootstrap.

Emit worker entry bundles as CommonJS .cjs files. pkg executes a VFS-backed
string-path worker through Module._compile, so an ESM-only entry can be
present in the executable yet still fail when launched. Keep the public hosts
ESM, adapt worker startup accordingly, and align exports, package file lists,
workspace constraints, documentation, and built-worker tests with the actual
artifact format.

Expand the custom-config executable smoke to load the Code Mode and workflow
plugins and script real run_code and zero-agent workflow calls. Require both
tools to return 42 from workers launched inside the pkg VFS, turning worker
support from an asset-presence assumption into an end-to-end runtime
contract.

Update the implemented RFC and verification gates to describe and exercise
the supported built-worker path. This adds no tool or JSON-RPC protocol shape;
it fixes how existing worker-backed capabilities are located and executed in
the single-file distribution.

packages/code-runtime/code-runtime-worker/src/index.ts

@@ -14,6 +14,7 @@
 
 import { Worker } from 'node:worker_threads'
 import { stripTypeScriptTypes } from 'node:module'
+import { fileURLToPath } from 'node:url'
 import { Context } from 'cordis'
 import z from 'schemastery'
 import { CodeRuntime } from '@deepseek-ai/dsh-code-runtime'
@@ -98,16 +99,19 @@ interface LiveRun {
 }
 
 /**
- * The worker entry module. Source runs unbuilt (`src/worker.ts`, loadable
+ * The worker entry path. Source runs unbuilt (`src/worker.ts`, loadable
  * directly on this repo's Node range via native type stripping — the file
  * is erasable-only with type-only relative imports); the built package
- * ships it as a sibling bundle (`lib/worker.js`, its own tsdown entry).
+ * ships it as a sibling CommonJS bundle (`lib/worker.cjs`, its own tsdown
+ * entry) because pkg's VFS Worker hook compiles string-path entries as
+ * CommonJS.
  * The URL *pathname*'s extension says which world this module is in —
  * pathname, because dev-time module runners (vitest) may suffix
- * `import.meta.url` with a query string; relative resolution drops it.
+ * `import.meta.url` with a query string; relative resolution drops it. Worker
+ * receives a filesystem string so pkg's VFS Worker hook can resolve it.
  */
-/* v8 ignore next -- the './worker.js' arm is the built-lib world, unreachable unbuilt by construction; the built-lib e2e pins it. */
-const WORKER_URL = new URL(new URL(import.meta.url).pathname.endsWith('.ts') ? './worker.ts' : './worker.js', import.meta.url)
+/* v8 ignore next -- the './worker.cjs' arm is the built-lib world, unreachable unbuilt by construction; the built-lib e2e pins it. */
+const WORKER_PATH = fileURLToPath(new URL(new URL(import.meta.url).pathname.endsWith('.ts') ? './worker.ts' : './worker.cjs', import.meta.url))
 
 /** Render an unknown thrown value as a message, `Error` or not. */
 function messageOf(error: unknown): string {
@@ -273,7 +277,7 @@ export class WorkerCodeRuntime extends CodeRuntime {
       maxLogBytes: this.config.maxLogBytes,
       maxValueBytes: this.config.maxValueBytes,
     }
-    const worker = new Worker(WORKER_URL, {
+    const worker = new Worker(WORKER_PATH, {
       workerData: bootData,
       // Model code gets NO ambient environment — stronger than the scrubbed
       // env the defensive-patterns rule requires for spawned commands.

packages/code-runtime/code-runtime-worker/src/worker.ts

@@ -17,4 +17,4 @@ import type { WorkerBootData } from './protocol.ts'
 // A worker always has a parent port; guard loudly rather than run detached.
 if (!parentPort) throw new Error('dsh-code-runtime-worker: worker entry loaded outside a worker thread')
 
-await runWorkerMain(parentPort, workerData as WorkerBootData, { stdout: process.stdout, stderr: process.stderr })
+void runWorkerMain(parentPort, workerData as WorkerBootData, { stdout: process.stdout, stderr: process.stderr })