fix: Windows encoding (UTF-8 BOM + CRLF) and macOS Gatekeeper

- Windows bat files: UTF-8 BOM + CRLF + English text to avoid garbled Chinese in cmd.exe
- macOS scripts: xattr -rd com.apple.quarantine to fix "unverified developer" popup
- New install scripts: Mac-安装并启动.command, Windows-安装并启动.bat
  (extract tar.gz to local disk then launch)

uclaw-scripts/Windows-安装并启动.bat

@@ -0,0 +1,79 @@
+@echo off
+chcp 65001 >nul 2>&1
+title U-Claw - Install and Launch
+
+echo.
+echo   ========================================
+echo     U-Claw v1.1
+echo     Install and Launch (Windows)
+echo   ========================================
+echo.
+
+set "USB_DIR=%~dp0"
+set "ARCHIVE=%USB_DIR%U-Claw.tar.gz"
+set "INSTALL_DIR=%USERPROFILE%\U-Claw"
+
+REM Check archive
+if not exist "%ARCHIVE%" (
+    echo   [ERROR] U-Claw.tar.gz not found
+    echo   Please ensure this script and the archive are in the same directory
+    echo.
+    pause
+    exit /b 1
+)
+
+REM Check if already installed
+if exist "%INSTALL_DIR%\openclaw\node_modules" (
+    echo   U-Claw already installed at: %INSTALL_DIR%
+    echo.
+    echo   [1] Launch directly (skip extract)
+    echo   [2] Reinstall (overwrite)
+    echo.
+    set /p choice="  Choose [1/2, default 1]: "
+    if "%choice%"=="2" (
+        echo.
+        echo   Reinstalling...
+        rmdir /s /q "%INSTALL_DIR%" >nul 2>&1
+    ) else (
+        echo.
+        echo   Launching...
+        goto :start
+    )
+)
+
+REM Extract
+echo.
+echo   Extracting U-Claw to %INSTALL_DIR% ...
+echo   This may take 1-2 minutes...
+echo.
+
+where tar >nul 2>&1
+if %errorlevel%==0 (
+    cd /d "%USERPROFILE%"
+    tar xzf "%ARCHIVE%"
+    if %errorlevel% neq 0 (
+        echo   Extract failed! Please extract U-Claw.tar.gz manually
+        echo   using 7-Zip or WinRAR to %USERPROFILE%
+        pause
+        exit /b 1
+    )
+) else (
+    echo   tar command not available on this Windows version
+    echo   Please extract U-Claw.tar.gz manually using 7-Zip or WinRAR
+    echo   Extract to: %USERPROFILE%
+    echo.
+    echo   Then run: %INSTALL_DIR%\Windows-从U盘启动.bat
+    pause
+    exit /b 1
+)
+
+echo   Extract complete!
+echo.
+
+:start
+REM Launch OpenClaw
+echo   Starting OpenClaw...
+echo.
+
+cd /d "%INSTALL_DIR%"
+call "%INSTALL_DIR%\Windows-从U盘启动.bat"