feat: build.ps1 produces Launcher.exe + portable layout

- build a lean onefile Launcher.exe from src/launcher.py (stdlib-only, no
  PySide6/Pillow) alongside the onedir app build
- release dir is now the portable layout: Launcher.exe + app\ (CMBot.exe +
  config + version.txt)
- emit two zips: CMBot-<ver>.zip (self-update payload = app\ contents, what
  manifest.url points to) and CMBot-<ver>-portable.zip (initial install)
- launcher: harden logging setup for --windowed builds / read-only roots

Actual PyInstaller build must run on Windows; script is syntax-verified.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tasks.md

@@ -934,7 +934,7 @@
 - [x] 文档：`docs/10` 改为便携 + `Launcher.exe` + `~/.cmbot` 模型（§3/§4/§5/§8/§9/§11/§16）
 - [x] `get_data_dir()` 三级回退：`CMBOT_DATA_DIR` → 打包态 `~/.cmbot` → 开发态项目根；`tests/test_file_service.py` 5 个单测
 - [x] `src/launcher.py`：复用 `update_service`，下载 zip→SHA-256→解压→`app/app.old` 切换→启动；安装根可写性检测；首次把 `app\config\` 默认模板播种到 `~/.cmbot`；`update_service` 扩展（`UpdateInfo.sha256/size/min_supported`、绝对 url 解析、`make_auth_header`/`download`）；`tests/test_launcher.py` 11 个单测 + 本地 HTTP server 真实端到端验证
-- [ ] `build.ps1` 增产 `Launcher.exe`（PyInstaller onefile），发布 zip 含 `Launcher.exe` + `app\`
+- [x] `build.ps1` 增产 `Launcher.exe`（PyInstaller onefile，console）；发布目录改为便携布局 `Launcher.exe` + `app\`；产出两个 zip——自更新载荷 `CMBot-<ver>.zip`（app\ 内容，manifest.url 指向它）与便携安装包 `CMBot-<ver>-portable.zip`；`launcher.py` 日志初始化健壮化（--windowed/只读根不崩）。语法校验通过；实际 PyInstaller 构建需在 Windows 跑
 - [ ] 退休 `scripts/update.ps1` 与 `scripts/install_local.ps1`
 - [ ] 端到端实测（解压到 D 盘运行、自更新、回滚）