feat(clients): 各客户端支持环境变量配置，Spring Boot 2 客户端优化选择性刷新

- Dockerfile.springboot2: 更换基础镜像为阿里云私有镜像
- .NET/SpringBoot2 demo: 配置项改为从环境变量读取，支持 Docker 传参
- Spring Boot 2 客户端: @Value/@ConfigurationProperties 刷新优化为只刷新受变更 key 影响的字段
- README_DOCKERFILE.md: 标注 .NET 客户端 Docker 测试通过

kenaito-conf-springboot2-client/src/main/java/cn/odboy/confcenter/ConfigcenterContext.java

@@ -333,6 +333,8 @@ public class ConfigcenterContext {
             result = LocalCacheUtils.read();
         } else {
             LocalCacheUtils.write(result);
+            int configCount = result.size();
+            logger.info("[ConfigClient] fetched {} configs", configCount);
         }
         return result;
     }
@@ -410,7 +412,7 @@ public class ConfigcenterContext {
 
             // Refresh @Value and @ConfigurationProperties fields
             logger.info("[RefreshScope] Calling refreshDynamicConfigFields()...");
-            refreshDynamicConfigFields();
+            refreshDynamicConfigFields(updateConfig.keySet());
             logger.info("[RefreshScope] refreshDynamicConfigFields() completed");
         }
     }
@@ -448,13 +450,13 @@ public class ConfigcenterContext {
             }
         }
         // Refresh @Value and @ConfigurationProperties fields
-        refreshDynamicConfigFields();
+        refreshDynamicConfigFields(new HashSet<>(keys));
     }
 
-    private void refreshDynamicConfigFields() {
+    private void refreshDynamicConfigFields(Set<String> changedKeys) {
         if (applicationContext != null) {
             try {
-                logger.info("[RefreshScope] Starting dynamic config field refresh...");
+                logger.info("[RefreshScope] Starting dynamic config field refresh for keys: {}", String.join(", ", changedKeys));
                 StandardEnvironment env = (StandardEnvironment) applicationContext.getEnvironment();
                 // 直接创建 RefreshScopeRegistry 并注册为 BeanPostProcessor
                 RefreshScopeRegistry registry = new RefreshScopeRegistry(env);
@@ -474,8 +476,8 @@ public class ConfigcenterContext {
                 configPropsCount = registry.getConfigPropsCount();
                 logger.info("[RefreshScope] Recorded {} @Value fields and {} @ConfigurationProperties beans", valueFieldCount, configPropsCount);
 
-                // 刷新
-                registry.refresh();
+                // 刷新（只刷新受影响的字段）
+                registry.refresh(changedKeys);
                 logger.info("[RefreshScope] RefreshScopeRegistry.refresh() completed, refreshed {} @Value fields and {} @ConfigurationProperties beans", registry.getValueFieldCount(), registry.getConfigPropsCount());
             } catch (Exception e) {
                 logger.warn("[RefreshScope] RefreshScopeRegistry.refresh() error, msg:{}", e.getMessage(), e);

kenaito-conf-springboot2-client/src/main/java/cn/odboy/confcenter/InternalConfigChangeListener.java

@@ -72,7 +72,10 @@ public class InternalConfigChangeListener {
 									logger.info("[ConfigClient] {} configs deleted: {}", deletedKeys.length, String.join(", ", deletedKeys));
 								}
 							}
-							if (!data.isEmpty()) context.updateConfig(data);
+							if (!data.isEmpty()) {
+								context.updateConfig(data);
+								logger.info("[ConfigClient] {} configs changed: {}", data.size(), String.join(", ", data.keySet()));
+							}
 						}
 					}
 				} catch (Exception e) {

kenaito-conf-springboot2-client/src/main/java/cn/odboy/confcenter/RefreshScopeRegistry.java

@@ -3,6 +3,7 @@ package cn.odboy.confcenter;
 import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -60,27 +61,29 @@ public class RefreshScopeRegistry implements BeanPostProcessor {
 	}
 
 	/**
-	 * Refresh all @Value fields and @ConfigurationProperties beans
+	 * Refresh only @Value fields and @ConfigurationProperties beans that are affected by changed keys
 	 */
-	public void refresh() {
-		refreshValueFields();
-		refreshConfigPropsBeans();
+	public void refresh(Set<String> changedKeys) {
+		refreshValueFields(changedKeys);
+		refreshConfigPropsBeans(changedKeys);
 	}
 
-	private void refreshValueFields() {
+	private void refreshValueFields(Set<String> changedKeys) {
 		for (ValueFieldHolder holder : valueFields) {
-			try {
-				holder.refresh(environment);
-			} catch (Exception e) {
-				// ignore refresh errors
+			if (changedKeys.contains(holder.key)) {
+				try {
+					holder.refresh(environment);
+				} catch (Exception e) {
+					// ignore refresh errors
+				}
 			}
 		}
 	}
 
-	private void refreshConfigPropsBeans() {
+	private void refreshConfigPropsBeans(Set<String> changedKeys) {
 		for (ConfigPropsHolder holder : configPropsBeans) {
 			try {
-				holder.refresh(environment);
+				holder.refresh(environment, changedKeys);
 			} catch (Exception e) {
 				// ignore refresh errors
 			}
@@ -149,24 +152,27 @@ public class RefreshScopeRegistry implements BeanPostProcessor {
 			this.bean = bean;
 		}
 
-		void refresh(Environment env) {
+		void refresh(Environment env, Set<String> changedKeys) {
 			Class<?> clazz = bean.getClass();
 			ConfigurationProperties anno = clazz.getAnnotation(ConfigurationProperties.class);
 			if (anno != null) {
 				String prefix = anno.prefix();
-				bindProperties(bean, prefix, env);
+				bindProperties(bean, prefix, env, changedKeys);
 			}
 		}
 
-		private void bindProperties(Object bean, String prefix, Environment env) {
+		private void bindProperties(Object bean, String prefix, Environment env, Set<String> changedKeys) {
 			try {
 				Class<?> clazz = bean.getClass();
 				for (Field field : getAllDeclaredFields(clazz)) {
 					String propertyName = prefix + "." + camelToKebab(field.getName());
-					String value = env.getProperty(propertyName);
-					if (value != null) {
-						field.setAccessible(true);
-						field.set(bean, convertType(field.getType(), value));
+					// Only refresh if this property key is in changedKeys
+					if (changedKeys.contains(propertyName)) {
+						String value = env.getProperty(propertyName);
+						if (value != null) {
+							field.setAccessible(true);
+							field.set(bean, convertType(field.getType(), value));
+						}
 					}
 				}
 			} catch (Exception e) {