fix: spawn launcher services without implicit shell (#16093)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 19deb2d0-75af-4fcf-ac1d-a6933c00769f

__tests__/scripts/dev-process-utils.test.ts

@@ -1,3 +1,6 @@
+import { spawn } from "node:child_process";
+import { once } from "node:events";
+
 import { describe, expect, it } from "vitest";
 
 import {
@@ -30,6 +33,28 @@ describe("dev process utils", () => {
       detached: process.platform !== "win32",
     });
   });
+
+  it("passes shell metacharacters to services as literal arguments", async () => {
+    const constraint = "agent-client-protocol<0.11";
+    const child = spawn(
+      process.execPath,
+      ["-e", "process.stdout.write(process.argv[1])", constraint],
+      getProcessTreeSpawnOptions({
+        shell: true,
+        stdio: ["ignore", "pipe", "pipe"],
+      }),
+    );
+    let stdout = "";
+    child.stdout.setEncoding("utf8");
+    child.stdout.on("data", (chunk) => {
+      stdout += chunk;
+    });
+
+    const [exitCode] = await once(child, "exit");
+
+    expect(exitCode).toBe(0);
+    expect(stdout).toBe(constraint);
+  });
 });
 
 describe("resolveWindowsCommand", () => {

scripts/dev-process-utils.mjs

@@ -15,7 +15,11 @@ export function isProcessRunning(proc) {
 }
 
 /**
- * Add spawn options needed for process-tree cleanup.
+ * Add spawn options needed for safe service launches and process-tree cleanup.
+ *
+ * Arguments must bypass shell parsing so values such as version constraints
+ * containing `<` are forwarded literally. Callers that need shell behavior
+ * must invoke the shell explicitly as the command.
  *
  * On POSIX, `detached: true` makes the spawned service the leader of a new
  * process group. Later we can signal `-pid` to terminate that whole group,
@@ -30,6 +34,7 @@ export function isProcessRunning(proc) {
 export function getProcessTreeSpawnOptions(options = {}) {
   return {
     ...options,
+    shell: false,
     detached: process.platform !== "win32",
   };
 }