fix(targets): use cmd.exe for escaped Windows wrapper launches

Align Windows .cmd/.bat launch behavior with the Codex detector shell contract.

This keeps escaped -c overrides intact through wrapper execution.

Adds regression coverage for the Codex runtime path and the shared Windows shell launch path.

src/targets/claude-adapter.ts

@@ -9,7 +9,12 @@ import { spawn, ChildProcess } from 'child_process';
 import { TargetAdapter, TargetBinaryInfo, TargetCredentials, TargetType } from './target-adapter';
 import { detectClaudeCli, getClaudeCliInfo } from '../utils/claude-detector';
 import type { ProfileType } from '../types/profile';
-import { escapeShellArg, stripAnthropicEnv, stripClaudeCodeEnv } from '../utils/shell-executor';
+import {
+  escapeShellArg,
+  getWindowsEscapedCommandShell,
+  stripAnthropicEnv,
+  stripClaudeCodeEnv,
+} from '../utils/shell-executor';
 import { ErrorManager } from '../utils/error-manager';
 import { getWebSearchHookEnv } from '../utils/websearch-manager';
 import { appendBrowserToolArgs } from '../utils/browser';
@@ -111,7 +116,7 @@ export class ClaudeAdapter implements TargetAdapter {
       child = spawn(cmdString, {
         stdio: 'inherit',
         windowsHide: true,
-        shell: true,
+        shell: getWindowsEscapedCommandShell(),
         env,
       });
     } else {

src/targets/codex-adapter.ts

@@ -4,7 +4,12 @@ import type { ProfileType } from '../types/profile';
 import { runCleanup } from '../errors';
 import { expandPath } from '../utils/helpers';
 import { wireChildProcessSignals } from '../utils/signal-forwarder';
-import { escapeShellArg, stripAnthropicEnv, stripCodexSessionEnv } from '../utils/shell-executor';
+import {
+  escapeShellArg,
+  getWindowsEscapedCommandShell,
+  stripAnthropicEnv,
+  stripCodexSessionEnv,
+} from '../utils/shell-executor';
 import type {
   TargetAdapter,
   TargetBinaryInfo,
@@ -316,7 +321,7 @@ export class CodexAdapter implements TargetAdapter {
       child = spawn(cmdString, {
         stdio: 'inherit',
         windowsHide: true,
-        shell: true,
+        shell: getWindowsEscapedCommandShell(),
         env: launchEnv,
       });
     } else {

src/targets/codex-detector.ts

@@ -1,7 +1,7 @@
 import * as fs from 'fs';
 import * as childProcess from 'child_process';
 import { expandPath } from '../utils/helpers';
-import { escapeShellArg } from '../utils/shell-executor';
+import { escapeShellArg, getWindowsEscapedCommandShell } from '../utils/shell-executor';
 import type { TargetBinaryInfo } from './target-adapter';
 
 const CODEX_CONFIG_OVERRIDE_FEATURE = 'config-overrides';
@@ -58,7 +58,7 @@ function runCodexProbe(codexPath: string, args: string[]): string | undefined {
         stdio: ['ignore', 'pipe', 'ignore'],
         timeout: 5000,
         windowsHide: true,
-        shell: 'cmd.exe',
+        shell: getWindowsEscapedCommandShell(),
       });
       return result.status === 0 ? result.stdout : undefined;
     }

src/targets/droid-adapter.ts

@@ -12,7 +12,11 @@ import { getDroidBinaryInfo, detectDroidCli, checkDroidVersion } from './droid-d
 import type { ProfileType } from '../types/profile';
 import { upsertCcsModel } from './droid-config-manager';
 import { resolveDroidProvider } from './droid-provider';
-import { escapeShellArg, stripAnthropicEnv } from '../utils/shell-executor';
+import {
+  escapeShellArg,
+  getWindowsEscapedCommandShell,
+  stripAnthropicEnv,
+} from '../utils/shell-executor';
 import { wireChildProcessSignals } from '../utils/signal-forwarder';
 import { runCleanup } from '../errors';
 
@@ -134,7 +138,7 @@ export class DroidAdapter implements TargetAdapter {
       child = spawn(cmdString, {
         stdio: 'inherit',
         windowsHide: true,
-        shell: true,
+        shell: getWindowsEscapedCommandShell(),
         env,
       });
     } else {

src/utils/shell-executor.ts

@@ -107,6 +107,16 @@ export function escapeShellArg(arg: string): string {
   }
 }
 
+/**
+ * Return the Windows shell that matches escapeShellArg() quoting semantics.
+ *
+ * `shell: true` is not strict enough for npm `.cmd` wrappers because Node may
+ * route through a different quoting path than the one escapeShellArg() expects.
+ */
+export function getWindowsEscapedCommandShell(): string {
+  return 'cmd.exe';
+}
+
 /**
  * Execute Claude CLI with unified spawn logic
  */
@@ -182,7 +192,7 @@ export function execClaude(
     child = spawn(cmdString, {
       stdio: 'inherit',
       windowsHide: true,
-      shell: true,
+      shell: getWindowsEscapedCommandShell(),
       env,
     });
   } else {

tests/unit/targets/codex-adapter-exec.test.ts

@@ -0,0 +1,115 @@
+import { afterEach, beforeEach, describe, expect, it, mock } from 'bun:test';
+import * as childProcess from 'child_process';
+import { EventEmitter } from 'events';
+import * as fs from 'fs';
+import * as os from 'os';
+import * as path from 'path';
+
+const spawnCalls: Array<{
+  command: string;
+  args: string[];
+  options: Record<string, unknown> | undefined;
+}> = [];
+const originalPlatform = process.platform;
+
+function createMockChild(): EventEmitter & {
+  stdout: EventEmitter;
+  stderr: EventEmitter;
+  exitCode: number | null;
+  killed: boolean;
+  pid: number;
+  unref: () => EventEmitter;
+  kill: () => boolean;
+} {
+  const child = new EventEmitter() as EventEmitter & {
+    stdout: EventEmitter;
+    stderr: EventEmitter;
+    exitCode: number | null;
+    killed: boolean;
+    pid: number;
+    unref: () => EventEmitter;
+    kill: () => boolean;
+  };
+
+  child.stdout = new EventEmitter();
+  child.stderr = new EventEmitter();
+  child.exitCode = null;
+  child.killed = false;
+  child.pid = process.pid;
+  child.unref = () => child;
+  child.kill = () => {
+    child.killed = true;
+    child.exitCode = 1;
+    return true;
+  };
+
+  return child;
+}
+
+mock.module('child_process', () => ({
+  ...childProcess,
+  spawn: (...spawnArgs: unknown[]) => {
+    const command = String(spawnArgs[0] ?? '');
+    const maybeArgs = spawnArgs[1];
+    const args = Array.isArray(maybeArgs) ? (maybeArgs as string[]) : [];
+    const options = (Array.isArray(maybeArgs) ? spawnArgs[2] : spawnArgs[1]) as
+      | Record<string, unknown>
+      | undefined;
+
+    spawnCalls.push({ command, args, options });
+    return createMockChild();
+  },
+}));
+
+mock.module('../../../src/utils/signal-forwarder', () => ({
+  wireChildProcessSignals: () => {},
+}));
+
+import { CodexAdapter } from '../../../src/targets/codex-adapter';
+import { buildCodexBrowserMcpOverrides } from '../../../src/utils/browser-codex-overrides';
+
+describe('codex-adapter exec', () => {
+  let tmpDir: string;
+
+  beforeEach(() => {
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'ccs-codex-adapter-exec-'));
+    spawnCalls.length = 0;
+  });
+
+  afterEach(() => {
+    Object.defineProperty(process, 'platform', { value: originalPlatform });
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+  });
+
+  it('launches Windows cmd wrappers via cmd.exe when runtime overrides include browser MCP args', () => {
+    Object.defineProperty(process, 'platform', { value: 'win32' });
+
+    const fakeCodex = path.join(tmpDir, 'codex.cmd');
+    fs.writeFileSync(fakeCodex, '');
+
+    const adapter = new CodexAdapter();
+    const binaryInfo = {
+      path: fakeCodex,
+      needsShell: true,
+      features: ['config-overrides'],
+    };
+    const args = adapter.buildArgs('default', ['--version'], {
+      profileType: 'default',
+      creds: {
+        profile: 'default',
+        baseUrl: '',
+        apiKey: '',
+        runtimeConfigOverrides: buildCodexBrowserMcpOverrides(),
+      },
+      binaryInfo,
+    });
+
+    adapter.exec(args, {}, { binaryInfo });
+
+    expect(spawnCalls).toHaveLength(1);
+    expect(spawnCalls[0]?.options?.shell).toBe('cmd.exe');
+    expect(spawnCalls[0]?.command).toContain(fakeCodex);
+    expect(spawnCalls[0]?.command).toContain('mcp_servers.ccs_browser.args=');
+    expect(spawnCalls[0]?.command).toContain('@playwright/mcp@0.0.70');
+  });
+});

tests/unit/utils/claudecode-env-stripping.test.ts

@@ -266,6 +266,7 @@ describe('CLAUDECODE environment stripping', () => {
     expect(spawnCalls.length).toBeGreaterThan(0);
     const env = spawnCalls[0].options?.env as NodeJS.ProcessEnv;
     expect(Object.keys(env).map((k) => k.toUpperCase())).not.toContain('CLAUDECODE');
+    expect(spawnCalls[0].options?.shell).toBe('cmd.exe');
   });
 
   it('execClaude sets DISABLE_AUTOUPDATER=1 when preferences.auto_update is false', () => {