fix(macos): align menu reapply and ChatGPT launch semantics

[EchoJamie]

Summary / 摘要

• Closes [Bug][macOS]: 菜单“重新应用皮肤”和“打开 ChatGPT”入口语义不一致 #341.
• “重新应用皮肤”现在先无弹窗尝试热重载；只有热重载不可用时，才根据状态提示打开或重启 ChatGPT。
  “重新应用皮肤” now attempts hot reapply first without showing a confirmation dialog; only when hot reapply is unavailable does it prompt to open or restart ChatGPT based on the current state.
• “打开 ChatGPT”保留原菜单标题，但改走 Dream Skin 启动/应用链路，不再只是原生打开官方 ChatGPT.app。
  “打开 ChatGPT” keeps the original menu title, but now uses the Dream Skin launch/apply path instead of only opening the official ChatGPT.app natively.
• 增加静态回归，锁住热重载顺序、打开/重启确认门槛，以及“打开 ChatGPT”入口不能回退到原生打开。
  Added static regressions that lock the hot-reapply ordering, open/restart confirmation gates, and prevent the “打开 ChatGPT” action from regressing to native app opening.
• 更新 macos/CHANGELOG.md 记录本次用户可见行为修复。
  Updated macos/CHANGELOG.md for this user-visible behavior fix.

Type / 类型

• Bug fix / 缺陷修复
• Feature / 新功能
• Docs / 文档
• Theme / CSS / visual / 主题或视觉
• Scripts / install / restore / 脚本或安装恢复
• Chore / 杂项

Platform / 平台

• macOS
• Windows
• Both / 双平台
• Docs / repo only / 仅文档或仓库元数据

Self-check / 自测

Docs-only / 仅文档

• Links and wording reviewed / 已检查链接与表述

macOS (when code under macos/ changes)

• macos/tests/run-tests.sh passed / 已通过
• Doctor (optional): macos/scripts/doctor-macos.sh
• Live verify (if inject/CSS/start path): verify-dream-skin-macos.sh or Desktop Verify
• Restore / re-apply smoke (if install/restore/start changed) / 若改了安装恢复启动则做过恢复再应用

Windows (when code under windows/ changes)

• Relevant install / start / verify / restore scripts exercised / 已按改动跑过对应脚本
• Environment noted below (OS build, Codex source) / 下方注明环境

User-facing / 用户可见变更

• Updated macos/CHANGELOG.md (and macos/VERSION if release-worthy) / 已更新 changelog（发版时再 bump VERSION）
• N/A — no user-facing change / 无用户可见变更

Security / 安全

• Does not modify official Codex install / asar / signatures / 未修改官方安装与签名
• Does not silently write API Base URL or keys / 未静默写入 API Base URL 或 Key
• CDP remains loopback-oriented (127.0.0.1) where applicable / CDP 仍仅本机回环（如适用）

Notes / 补充

• 本地验证已通过：
  Local validation passed:

  • bash -n macos/scripts/apply-from-menubar-macos.sh
  • bash -n macos/tests/run-tests.sh
  • git diff --check
  • swift build --package-path macos/menubar-app --product CodexDreamSkinMenuBar
  • CODEX_DREAM_SKIN_SKIP_DOCTOR=1 bash macos/tests/run-tests.sh
  • bash macos/scripts/doctor-macos.sh
  • bash macos/scripts/verify-dream-skin-macos.sh
  • bash macos/scripts/doctor-macos.sh --require-live

• Doctor 已在以下环境通过：macOS 15.5 (24F74)、Apple Silicon、官方 /Applications/ChatGPT.app 版本 26.730.61639、build 6234、Team ID 2DC432GLL2、内置 Node v24.14.0。
  Doctor passed on macOS 15.5 (24F74), Apple Silicon, official /Applications/ChatGPT.app version 26.730.61639, build 6234, Team ID 2DC432GLL2, bundled Node v24.14.0.

• Live verify 已通过：端口 9341 上的本机回环 CDP 会话可验证，主题 noir-mono 已应用，首页 L1 结构、侧栏、主区可见，且无 document overflow。
  Live verify passed: the loopback CDP session on port 9341 was verified, theme noir-mono was applied, the home L1 structure, sidebar, and main area were visible, and there was no document overflow.

• Restore / re-apply smoke 未执行；本轮不勾选该项。
  Restore / re-apply smoke was not run; this item is intentionally left unchecked for this PR.

• 直接运行 swift test --package-path macos/menubar-app 在本机受阻，因为当前 Swift 工具链无法导入 XCTest；仓库 macOS 测试包装器已识别缺少完整匹配 Xcode 平台并跳过 native XCTest。
  Direct swift test --package-path macos/menubar-app is blocked on this host because the current Swift toolchain cannot import XCTest; the repository macOS test wrapper detects the missing full matching Xcode platform and skips native XCTest.

• 本 PR 不修改官方 ChatGPT/Codex App 文件、签名、app.asar、API Key 或 API Base URL。
  This PR does not modify official ChatGPT/Codex app files, signatures, app.asar, API keys, or API Base URL.