chore: 删除多个客户端模块

移除以下未完成的客户端模块：
- C++ 客户端和 demo
- .NET 客户端和 demo
- Kotlin 客户端和 demo
- Lua 客户端和 demo
- PHP 客户端和 demo
- Ruby 客户端和 demo
- Rust 客户端和 demo

更新根目录 README.md，移除相关说明。

kenaito-conf-cpp-client/README.md

@@ -1,48 +0,0 @@
-# Kenaito Config Center C++ Client
-
-C++ 语言的配置中心客户端 SDK，使用 libcurl。
-
-## 依赖
-
-- libcurl
-- C++17
-
-### macOS
-
-```bash
-brew install curl
-```
-
-### Ubuntu/Debian
-
-```bash
-apt-get install libcurl4-openssl-dev
-```
-
-## 编译
-
-```bash
-cd kenaito-conf-cpp-client-demo
-g++ -std=c++17 -o demo ../kenaito-conf-cpp-client/main.cpp -lcurl -lpthread
-./demo
-```
-
-## 功能
-
-- HTTP POST 拉取配置
-- 定时同步
-- 变更回调
-- 线程安全
-
-## 配置参数
-
-| 参数 | 说明 | 默认值 |
-|------|------|--------|
-| `baseUrl` | 配置中心地址 | 必填 |
-| `appName` | 应用名称 | 必填 |
-| `env` | 环境 | `dev` |
-| `version` | 配置版本 | `latest` |
-| `token` | 认证令牌 | 空 |
-| `syncInterval` | 同步间隔（秒） | `60` |
-| `ignoreGlobal` | 是否忽略全局配置 | `false` |
-| `cacheDir` | 本地缓存目录 | `.` |

kenaito-conf-cpp-client/main.cpp

@@ -1,106 +0,0 @@
-#include <iostream>
-#include <string>
-#include <map>
-#include <vector>
-#include <functional>
-#include <thread>
-#include <mutex>
-#include <atomic>
-#include <chrono>
-#include <fstream>
-#include <sstream>
-#include <cstring>
-#include <curl/curl.h>
-
-namespace kenaito_conf {
-
-struct Config {
-    std::string baseUrl;
-    std::string appName;
-    std::string env = "dev";
-    std::string version = "latest";
-    std::string token;
-    int syncInterval = 60;
-    bool ignoreGlobal = false;
-    std::string cacheDir = ".";
-};
-
-class ConfigClient {
-public:
-    ConfigClient(const Config &config) : config_(config) {}
-
-    void onChange(std::function<void(const std::map<std::string, std::string> &)> handler) {
-        handlers_.push_back(handler);
-    }
-
-    std::string get(const std::string &key) {
-        std::lock_guard<std::mutex> lock(mutex_);
-        auto it = configs_.find(key);
-        return it != configs_.end() ? it->second : "";
-    }
-
-    std::map<std::string, std::string> getAll() {
-        std::lock_guard<std::mutex> lock(mutex_);
-        return configs_;
-    }
-
-    void start() {
-        if (started_) return;
-        started_ = true;
-        fetchAll();
-        running_ = true;
-        syncThread_ = std::thread([this]() {
-            while (running_) {
-                std::this_thread::sleep_for(std::chrono::seconds(config_.syncInterval));
-                if (!running_) break;
-                try { fetchChanged(); } catch (...) {}
-            }
-        });
-    }
-
-    void stop() {
-        running_ = false;
-        if (syncThread_.joinable()) syncThread_.join();
-    }
-
-private:
-    Config config_;
-    std::map<std::string, std::string> configs_;
-    long lastTime_ = 0;
-    bool started_ = false;
-    std::atomic<bool> running_{false};
-    std::mutex mutex_;
-    std::thread syncThread_;
-    std::vector<std::function<void(const std::map<std::string, std::string> &)>> handlers_;
-
-    void fetchAll() { /* HTTP POST to /api/fetchAllConfigs */ }
-    void fetchChanged() { /* HTTP POST to /api/fetchChangedConfigs */ }
-};
-
-} // namespace kenaito_conf
-
-int main() {
-    std::cout << "Kenaito Config Center C++ Client Demo" << std::endl;
-
-    kenaito_conf::Config config;
-    config.baseUrl = "http://localhost:8080";
-    config.appName = "kenaito-springboot-demo";
-    config.env = "daily";
-    config.version = "latest";
-    config.syncInterval = 30;
-
-    kenaito_conf::ConfigClient client(config);
-
-    client.onChange([](const std::map<std::string, std::string> &changed) {
-        for (auto &[k, v] : changed)
-            std::cout << "config changed: " << k << " = " << v << std::endl;
-    });
-
-    client.start();
-    std::cout << "database.host = " << client.get("database.host") << std::endl;
-    std::cout << "Listening for changes... (press Ctrl+C to stop)" << std::endl;
-
-    std::cin.get();
-    client.stop();
-    return 0;
-}