fix: 渠道账号群聊同步缓存 key 及成员名称兜底；统一 Docker/Maven 项目约定

backend/pom.xml

@@ -84,6 +84,28 @@
                 </plugin>
             </plugins>
         </pluginManagement>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-toolchains-plugin</artifactId>
+                <version>3.2.0</version>
+                <configuration>
+                    <toolchains>
+                        <jdk>
+                            <version>21</version>
+                            <vendor>zulu</vendor>
+                        </jdk>
+                    </toolchains>
+                </configuration>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>toolchain</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
     </build>
 
     <repositories>