fix(workers): isolate compiled host selectors

packages/utils/src/worker-host.ts

@@ -1,5 +1,13 @@
 import { stripWindowsExtendedLengthPathPrefix } from "./path";
 
+/** Prefix reserved for argv selectors dispatched by the shared CLI worker host. */
+export const WORKER_HOST_SELECTOR_PREFIX = "__omp_worker_";
+
+/** Whether an argv value selects a worker hosted by the shared CLI entrypoint. */
+export function isWorkerHostSelector(value: string | undefined): value is string {
+	return value?.startsWith(WORKER_HOST_SELECTOR_PREFIX) ?? false;
+}
+
 /**
  * Main-module path declared by self-dispatching CLI entrypoints — entries
  * whose top-level argv handling routes hidden `__omp_*` worker selectors.

packages/utils/test/worker-host.test.ts

@@ -1,6 +1,11 @@
 import { afterEach, beforeEach, describe, expect, it } from "bun:test";
 import { EventEmitter } from "node:events";
-import { consumeWorkerInbox, installWorkerInbox } from "../src/worker-host";
+import {
+	consumeWorkerInbox,
+	installWorkerInbox,
+	isWorkerHostSelector,
+	WORKER_HOST_SELECTOR_PREFIX,
+} from "../src/worker-host";
 
 /**
  * Regression for JS/tab eval workers always stalling until the init timeout.
@@ -14,6 +19,16 @@ import { consumeWorkerInbox, installWorkerInbox } from "../src/worker-host";
  * buffers until the worker module `bind`s the real handler; these tests pin that
  * buffer-replay contract.
  */
+describe("worker-host selectors", () => {
+	it("recognizes the shared selector namespace without claiming ordinary CLI arguments", () => {
+		expect(WORKER_HOST_SELECTOR_PREFIX).toBe("__omp_worker_");
+		expect(isWorkerHostSelector("__omp_worker_stats_sync")).toBeTrue();
+		expect(isWorkerHostSelector("__omp_worker_computer")).toBeTrue();
+		expect(isWorkerHostSelector("--version")).toBeFalse();
+		expect(isWorkerHostSelector(undefined)).toBeFalse();
+	});
+});
+
 describe("worker-host inbox", () => {
 	// State is a module-global stash (one worker per process); drain it around
 	// each test so nothing leaks into the next.