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-rust-client-demo/Cargo.toml

@@ -1,8 +0,0 @@
-[package]
-name = "kenaito-conf-demo"
-version = "1.0.0"
-edition = "2021"
-
-[dependencies]
-kenaito-conf = { path = "../kenaito-conf-rust-client" }
-tokio = { version = "1", features = ["full"] }

kenaito-conf-rust-client-demo/src/main.rs

@@ -1,52 +0,0 @@
-use kenaito_conf::{Config, ConfigClient};
-use std::collections::HashMap;
-
-#[tokio::main]
-async fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let mut config_values: HashMap<String, String> = HashMap::new();
-    config_values.insert("database.host".to_string(), std::env::var("DATABASE_HOST").unwrap_or_else(|_| "192.168.1.1".to_string()));
-    config_values.insert("database.port".to_string(), std::env::var("DATABASE_PORT").unwrap_or_else(|_| "8888".to_string()));
-    config_values.insert("database.name".to_string(), std::env::var("DATABASE_NAME").unwrap_or_else(|_| "xxxx".to_string()));
-    config_values.insert("database.user".to_string(), std::env::var("DATABASE_USER").unwrap_or_else(|_| "xxxx".to_string()));
-    config_values.insert("database.password".to_string(), std::env::var("DATABASE_PASSWORD").unwrap_or_else(|_| "xxxxxxxx".to_string()));
-
-    let config = Config {
-        base_url: std::env::var("KENAITO_BASE_URL").unwrap_or_else(|_| "http://localhost:8080".to_string()),
-        app_name: std::env::var("KENAITO_APP_NAME").unwrap_or_else(|_| "kenaito-springboot-demo".to_string()),
-        env: std::env::var("KENAITO_PROFILE").unwrap_or_else(|_| "daily".to_string()),
-        version: std::env::var("KENAITO_VERSION").unwrap_or_else(|_| "latest".to_string()),
-        token: std::env::var("KENAITO_TOKEN").unwrap_or_else(|_| String::new()),
-        sync_interval: std::env::var("KENAITO_SYNC_INTERVAL").unwrap_or_else(|_| "30".to_string()).parse().unwrap_or(30),
-        cache_dir: std::env::var("KENAITO_CACHE_DIR").unwrap_or_else(|_| ".".to_string()),
-        ..Default::default()
-    };
-
-    let client = ConfigClient::new(config);
-
-    client.on_change(move |changed| {
-        for (k, v) in changed.iter() {
-            eprintln!("config changed: {} = {}", k, v);
-        }
-    });
-
-    match client.start().await {
-        Ok(_) => {
-            let remote = client.get_all();
-            eprintln!("loaded {} configs from remote", remote.len());
-        }
-        Err(e) => {
-            eprintln!("failed to init config client: {}", e);
-        }
-    }
-
-    println!("Current configs:");
-    for (k, v) in &config_values {
-        println!("  {} = {}", k, v);
-    }
-
-    println!("\nListening for config changes... (press Ctrl+C to stop)");
-    tokio::signal::ctrl_c().await?;
-    println!("Shutting down...");
-
-    Ok(())
-}