chore: add .gitattributes to fix cross-platform line endings

.gitattributes

@@ -0,0 +1,17 @@
+# 跨平台行尾：仓库内统一 LF，避免 Windows autocrlf 造成「假 modified」
+* text=auto eol=lf
+
+# Windows 批处理在 cmd 下需要 CRLF
+*.bat text eol=crlf
+*.cmd text eol=crlf
+
+# 二进制
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.ico binary
+*.webp binary
+*.woff binary
+*.woff2 binary
+*.exe binary

build.bat

@@ -1,4 +1,4 @@
 @echo off
-REM 姜十三论坛 Windows 快捷构建（双击或命令行均可）
+REM Jiang13 Forum Windows build wrapper (double-click or run from cmd)
 powershell -NoProfile -ExecutionPolicy Bypass -File "%~dp0build.ps1" %*
 exit /b %ERRORLEVEL%