fix: 修复Windows打包脚本依赖检查

- 检查 Python 是否正确安装
- 检查 PyQt6 是否可用
- 如果缺失则自动安装
- 提供清晰的错误提示和安装指引

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

build.bat

@@ -3,23 +3,85 @@ REM ================================
 REM CutThenThink Windows Build Script
 REM ================================
 
-REM Change to project directory and run packaging
+REM Change to project directory
 cd /d "%~dp0"
 
-REM Run PyInstaller packaging
-python -m PyInstaller --noconfirm --name "CutThenThink" --windowed --onefile --add-data "src:src" --hidden-import=PyQt6.QtCore --hidden-import=PyQt6.QtGui --hidden-import=PyQt6.QtWidgets --hidden-import=sqlalchemy src/main.py
+REM Check Python installation
+python --version 2>nul
 if errorlevel 1 (
-    echo Build Failed!
+    echo Error: Python not found
+    echo Please install Python 3.8+ from python.org
     pause
     exit /b 1
 )
 
+REM Check PyInstaller
+python -m PyInstaller --version 2>nul
+if errorlevel 1 (
+    echo.
+    echo PyInstaller not found, installing now...
+    python -m pip install --user pyinstaller
+)
+    echo.
+)
+if errorlevel 1 (
+    echo.
+    echo Trying PyInstaller from pip...
+    python -m pip install --user pyinstaller 2>nul
+)
+if errorlevel 1 (
+    echo.
+    echo PyInstaller still not available. Please install manually:
+    echo pip install pyinstaller
+    pause
+    exit /b 1
+)
+
+REM Check PyQt6 availability
+python -c "import PyQt6.QtCore" 2>nul
+if errorlevel 1 (
+    echo.
+    echo Warning: PyQt6 not installed
+    echo.
+)
+echo.
+echo 1/5. Installing dependencies...
+python -m pip install --user --upgrade pip 2>nul
+python -m pip install --user pyqt6 2>nul
+python -m pip install --user pyqt6-webengine 2>nul
+python -m pip install --user sqlalchemy 2>nul
+python -m pip install --user pyyaml 2>nul
+python -m pip install --user requests 2>nul
+python -m pip install --user pillow 2>nul
+python -m pip install --user pyperclip 2>nul
+
+echo.
+echo 2/5. Creating lightweight package (without PaddleOCR)...
+python -m pip install --user pyinstaller 2>nul
+findstr /V "paddleocr" /V "paddlepaddle" requirements.txt > nul
+if errorlevel 1 (
+    echo Error creating requirements_lite.txt
+    pause
+    exit /b 1
+)
+
+echo.
+echo 3/5. Building lightweight version...
+python -m PyInstaller --noconfirm --name "CutThenThink" --windowed --onefile --add-data "src:src" --hidden-import=PyQt6.QtCore --hidden-import=PyQt6.QtGui --hidden-import=PyQt6.QtWidgets --hidden-import=sqlalchemy src/main.py
+if errorlevel 1 (
+    echo Build Failed!
+    echo.
+    pause
+    exit /b 1
+)
+
+echo.
 echo ================================
 echo Build Complete!
 echo Executable: dist\CutThenThink.exe
 echo File size (without PaddleOCR): ~30-50 MB
 echo ================================
 echo.
-echo On first run, the app will auto-download and install PaddleOCR.
+echo On first run, app will auto-download and install PaddleOCR.
 echo.
 pause