修复前端打包和环境变量配置问题

- 添加 frontend-maven-plugin 自动构建前端
- 添加资源复制插件将前端打包到 JAR
- 修复环境变量名称（APP_DOMAIN）
- 配置 GitHub Actions 自动同步环境变量

Author: Layau-code

pom.xml

@@ -150,6 +150,75 @@
 
     <build>
         <plugins>
+            <!-- 前端构建插件 -->
+            <plugin>
+                <groupId>com.github.eirslett</groupId>
+                <artifactId>frontend-maven-plugin</artifactId>
+                <version>1.15.0</version>
+                <configuration>
+                    <workingDirectory>web</workingDirectory>
+                    <installDirectory>target</installDirectory>
+                </configuration>
+                <executions>
+                    <!-- 安装 Node.js 和 npm -->
+                    <execution>
+                        <id>install node and npm</id>
+                        <goals>
+                            <goal>install-node-and-npm</goal>
+                        </goals>
+                        <configuration>
+                            <nodeVersion>v18.20.5</nodeVersion>
+                            <npmVersion>10.8.2</npmVersion>
+                        </configuration>
+                    </execution>
+                    <!-- 安装前端依赖 -->
+                    <execution>
+                        <id>npm install</id>
+                        <goals>
+                            <goal>npm</goal>
+                        </goals>
+                        <configuration>
+                            <arguments>ci</arguments>
+                        </configuration>
+                    </execution>
+                    <!-- 构建前端 -->
+                    <execution>
+                        <id>npm run build</id>
+                        <goals>
+                            <goal>npm</goal>
+                        </goals>
+                        <configuration>
+                            <arguments>run build</arguments>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            
+            <!-- 资源复制插件 -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-resources-plugin</artifactId>
+                <version>3.3.1</version>
+                <executions>
+                    <execution>
+                        <id>copy-frontend-build</id>
+                        <phase>prepare-package</phase>
+                        <goals>
+                            <goal>copy-resources</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>${project.build.directory}/classes/static</outputDirectory>
+                            <resources>
+                                <resource>
+                                    <directory>web/dist</directory>
+                                    <filtering>false</filtering>
+                                </resource>
+                            </resources>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>