refactor(api): fetchAllConfigs 接口从 GET 改为 POST

- 服务端: 新增 FetchAllRequest 结构体，参数通过 JSON body 传递
- 服务端: 路由从 api.GET 改为 api.POST
- Go/Python/Node.js/Java 客户端同步更新为 POST + JSON body
- 与 fetchChangedConfigs 接口风格统一，token 不再暴露在 URL 中

kenaito-conf-springboot3-client/src/main/java/cn/odboy/confcenter/ConfigcenterContext.java

@@ -256,12 +256,19 @@ public class ConfigcenterContext {
 		String errorMsg = null;
 
 		for (String apiBaseUrl : apiBaseUrls) {
-			String url = buildTokenParameter(String.format("%s/api/fetchAllConfigs?appName=%s&env=%s&version=%s&ignoreGlobal=%s",
-					apiBaseUrl, app, env, version, ignoreGlobal));
+			String url = apiBaseUrl + "/api/fetchAllConfigs";
+			Map<String, Object> params = new HashMap<>();
+			params.put("appName", app);
+			params.put("env", env);
+			params.put("version", version);
+			params.put("ignoreGlobal", ignoreGlobal);
+			if (token != null && !token.isEmpty()) {
+				params.put("token", token);
+			}
 			System.out.println("fetch configs url:" + url);
 
 			try {
-				String jsonString = HttpUtils.get(url);
+				String jsonString = HttpUtils.postJson(url, objectMapper.writeValueAsString(params));
 				if (jsonString != null) {
 					result = objectMapper.readValue(jsonString, Map.class);
 					if (result.containsKey("code")) {