feat(devcontainer): add enhanced Maven development environment with Java 21, Bun, and SSH support

- Add Docker Compose configuration for Maven + Java 21 development container
- Include SSH server support for remote development (Zed editor compatible)
- Install Bun package manager and opencode-ai for enhanced development workflow
- Provide Makefile with commands for build, up, down, restart, logs, shell, ssh, and clean
- Add .env.example template for configurable ports and paths
- Include .gitignore for Java/Maven artifacts and IDE files
- Configure USTC mirrors for faster package installation
- Support persistent volume mounting for root user configuration (.ssh, .m2 cache)

java-maven/vibe-enhance-version/.gitignore

@@ -0,0 +1,20 @@
+# === 敏感配置与本地环境 ===
+.env
+.DS_Store
+
+# === Java/Maven 编译产物 ===
+target/
+*.class
+*.jar
+*.war
+*.ear
+*.log
+
+# === IDE 配置文件 (可选，视团队规范而定) ===
+.idea/
+.vscode/
+*.iml
+.classpath
+.project
+.settings/
+