添加 macOS 安装包打包支持

- 重命名 parser.py → xl_parser.py 避免与 Python 3.9 stdlib 命名冲突
- 添加 PyInstaller spec 文件用于构建独立 Python 可执行文件
- 配置 electron-builder：extraResources 打包 Python binary、asarUnpack better-sqlite3
- 新增 build:python 和 dist 脚本，一键生成 DMG 安装包
- 更新测试：对齐新 fixture 结构和重命名后的模块

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

python/main.py

@@ -10,7 +10,7 @@ def main():
             req = json.loads(line)
             action = req.get("action")
             if action == "parse_template":
-                from parser import parse_template
+                from xl_parser import parse_template
                 result = parse_template(req["file_path"])
             elif action == "generate":
                 from generator import generate

python/main.spec

@@ -0,0 +1,49 @@
+# -*- mode: python ; coding: utf-8 -*-
+from PyInstaller.utils.hooks import collect_all
+
+datas = []
+binaries = []
+hiddenimports = ['xl_parser', 'generator']
+tmp_ret = collect_all('openpyxl')
+datas += tmp_ret[0]; binaries += tmp_ret[1]; hiddenimports += tmp_ret[2]
+tmp_ret = collect_all('et_xmlfile')
+datas += tmp_ret[0]; binaries += tmp_ret[1]; hiddenimports += tmp_ret[2]
+tmp_ret = collect_all('PIL')
+datas += tmp_ret[0]; binaries += tmp_ret[1]; hiddenimports += tmp_ret[2]
+
+
+a = Analysis(
+    ['main.py'],
+    pathex=[],
+    binaries=binaries,
+    datas=datas,
+    hiddenimports=hiddenimports,
+    hookspath=[],
+    hooksconfig={},
+    runtime_hooks=[],
+    excludes=[],
+    noarchive=False,
+    optimize=0,
+)
+pyz = PYZ(a.pure)
+
+exe = EXE(
+    pyz,
+    a.scripts,
+    a.binaries,
+    a.datas,
+    [],
+    name='main',
+    debug=False,
+    bootloader_ignore_signals=False,
+    strip=False,
+    upx=True,
+    upx_exclude=[],
+    runtime_tmpdir=None,
+    console=True,
+    disable_windowed_traceback=False,
+    argv_emulation=False,
+    target_arch=None,
+    codesign_identity=None,
+    entitlements_file=None,
+)