feat(board-generator): add board code generator and sample CRUD artifacts

Add Node.js CLI tool with Handlebars templates for generating standard CRUD artifacts: Java entity, service, DAO, controller, MyBatis mapper XML, and Vue frontend pages.
Also generate the full SampleTableBoard CRUD reference implementation, update README with backend execution instructions, and add project plan documentation.

tools/board-generator/templates/serviceImpl.hbs

@@ -0,0 +1,52 @@
+package {{implPackage}};
+
+import java.util.List;
+
+import org.springframework.stereotype.Service;
+
+import {{rootPackage}}.{{serviceName}};
+import {{daoPackage}}.{{daoName}};
+import {{entityFqcn}};
+
+@Service
+public class {{serviceImplName}} implements {{serviceName}} {
+
+	private final {{daoName}} {{entityVarName}}Dao;
+
+	public {{serviceImplName}}({{daoName}} {{entityVarName}}Dao) {
+
+		this.{{entityVarName}}Dao = {{entityVarName}}Dao;
+	}
+
+	@Override
+	public List<{{entityName}}> get{{entityName}}List() {
+
+		return {{entityVarName}}Dao.select{{entityName}}List();
+	}
+
+	@Override
+	public {{entityName}} get{{entityName}}({{primaryKeyJavaType}} {{primaryKeyProperty}}) {
+
+		return {{entityVarName}}Dao.select{{entityName}}({{primaryKeyProperty}});
+	}
+
+	@Override
+	public {{entityName}} create{{entityName}}({{entityName}} {{entityVarName}}) {
+
+		{{entityVarName}}Dao.insert{{entityName}}({{entityVarName}});
+		return {{entityVarName}}Dao.select{{entityName}}({{entityVarName}}.{{primaryKeyGetterName}}());
+	}
+
+	@Override
+	public {{entityName}} update{{entityName}}({{entityName}} {{entityVarName}}) {
+
+		{{entityVarName}}Dao.update{{entityName}}({{entityVarName}});
+		return {{entityVarName}}Dao.select{{entityName}}({{entityVarName}}.{{primaryKeyGetterName}}());
+	}
+
+	@Override
+	public void delete{{entityName}}({{primaryKeyJavaType}} {{primaryKeyProperty}}) {
+
+		{{entityVarName}}Dao.delete{{entityName}}({{primaryKeyProperty}});
+	}
+}