fix(windows): align escaped wrapper shell handling

Use ComSpec-aware shell selection for escaped wrapper launches.

Apply it to the remaining Windows Claude launch paths.

Rewrite the Codex exec regression test to use scoped spies so the full suite stays isolated.

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

@@ -1,16 +1,13 @@
-import { afterEach, beforeEach, describe, expect, it, mock } from 'bun:test';
+import { afterEach, beforeEach, describe, expect, it, spyOn } 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;
+import { CodexAdapter } from '../../../src/targets/codex-adapter';
+import { buildCodexBrowserMcpOverrides } from '../../../src/utils/browser-codex-overrides';
+import * as signalForwarder from '../../../src/utils/signal-forwarder';
 
 function createMockChild(): EventEmitter & {
   stdout: EventEmitter;
@@ -46,34 +43,12 @@ function createMockChild(): EventEmitter & {
   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', () => {
+  const originalPlatform = process.platform;
   let tmpDir: string;
 
   beforeEach(() => {
     tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'ccs-codex-adapter-exec-'));
-    spawnCalls.length = 0;
   });
 
   afterEach(() => {
@@ -87,29 +62,45 @@ describe('codex-adapter exec', () => {
     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,
-    });
+    const spawnSpy = spyOn(childProcess, 'spawn').mockImplementation(
+      () => createMockChild() as unknown as ReturnType<typeof childProcess.spawn>
+    );
+    const signalSpy = spyOn(signalForwarder, 'wireChildProcessSignals').mockImplementation(
+      () => undefined
+    );
 
-    adapter.exec(args, {}, { binaryInfo });
+    try {
+      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,
+      });
 
-    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');
+      adapter.exec(args, {}, { binaryInfo });
+
+      expect(spawnSpy).toHaveBeenCalledTimes(1);
+      const [command, options] = spawnSpy.mock.calls[0] as [
+        string,
+        Record<string, unknown> | undefined,
+      ];
+      expect(options?.shell).toBe('cmd.exe');
+      expect(command).toContain(fakeCodex);
+      expect(command).toContain('mcp_servers.ccs_browser.args=');
+      expect(command).toContain('@playwright/mcp@0.0.70');
+    } finally {
+      spawnSpy.mockRestore();
+      signalSpy.mockRestore();
+    }
   });
 });