Enhance build scripts with datetime versioning

- Add datetime-based version tagging (YYYYMMDD_HHMMSS format)
- Support both automatic versioning and manual version override
- Build with both latest and version tags simultaneously
- Update both Linux (.sh) and Windows (.bat) build scripts
- Add detailed build output with next steps guidance

🤖 Generated with [Claude Code](https://claude.ai/code)

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

build.bat

@@ -1 +1,31 @@
-docker build -t xwindow-korean-dotnet:latest .
+@echo off
+REM Docker 이미지 빌드 배치 파일
+
+setlocal enabledelayedexpansion
+
+set IMAGE_NAME=xwindow-korean-dotnet
+
+REM 버전 태그 설정 (날짜시간 기반 또는 인자로 받기)
+if not "%1"=="" (
+    set VERSION=%1
+) else (
+    for /f "tokens=2-4 delims=/ " %%a in ('date /t') do set DATE=%%c%%a%%b
+    for /f "tokens=1-2 delims=: " %%a in ('time /t') do set TIME=%%a%%b
+    set TIME=!TIME: =0!
+    set VERSION=!DATE!_!TIME!
+)
+
+echo 🐳 Building Docker image: %IMAGE_NAME%:latest and %IMAGE_NAME%:!VERSION!
+
+REM 빌드 시작 (latest와 버전 태그 동시 적용)
+docker build -t %IMAGE_NAME%:latest -t %IMAGE_NAME%:!VERSION! .
+
+echo ✅ Build completed successfully!
+echo 🏷️  Tagged as:
+echo    - %IMAGE_NAME%:latest
+echo    - %IMAGE_NAME%:!VERSION!
+echo 📋 Next steps:
+echo    - Test: docker run -p 3389:3389 %IMAGE_NAME%:!VERSION!
+echo    - Push both tags: docker push %IMAGE_NAME%:latest ^&^& docker push %IMAGE_NAME%:!VERSION!
+
+pause