refactor(rpc): Centralize RPC service and unify API (#1427)

This change introduces a major refactoring of the RPC service layer to improve modularity, unify the API, and simplify the overall architecture.

Key changes:
- Replaced per-network-instance RPC services with a single global RPC server, reducing resource usage and simplifying management.
- All clients (CLI, Web UI, etc.) now interact with EasyTier core through a unified RPC entrypoint, enabling consistent authentication and control.
- RPC implementation logic has been moved to `easytier/src/rpc_service/` and organized by functionality (e.g., `instance_manage.rs`, `peer_manage.rs`, `config.rs`) for better maintainability.
- Standardized Protobuf API definitions under `easytier/src/proto/` with an `api_` prefix (e.g., `cli.proto` → `api_instance.proto`) to provide a consistent interface.
- CLI commands now require explicit `--instance-id` or `--instance-name` when multiple network instances are running; the parameter is optional when only one instance exists.

BREAKING CHANGE:  
RPC portal configuration (`rpc_portal` and `rpc_portal_whitelist`) has been removed from per-instance configs and the Web UI. The RPC listen address must now be specified globally via the `--rpc-portal` command-line flag or the `ET_RPC_PORTAL` environment variable, as there is only one RPC service for the entire application.

easytier/src/rpc_service/logger.rs

@@ -0,0 +1,105 @@
+use std::sync::{mpsc::Sender, Mutex, OnceLock};
+
+use crate::proto::{
+    api::logger::{
+        GetLoggerConfigRequest, GetLoggerConfigResponse, LogLevel, LoggerRpc,
+        SetLoggerConfigRequest, SetLoggerConfigResponse,
+    },
+    rpc_types::{self, controller::BaseController},
+};
+
+pub static LOGGER_LEVEL_SENDER: std::sync::OnceLock<Mutex<Sender<String>>> = OnceLock::new();
+pub static CURRENT_LOG_LEVEL: std::sync::OnceLock<Mutex<String>> = OnceLock::new();
+
+#[derive(Clone, Default)]
+pub struct LoggerRpcService;
+
+impl LoggerRpcService {
+    fn log_level_to_string(level: LogLevel) -> String {
+        match level {
+            LogLevel::Disabled => "off".to_string(),
+            LogLevel::Error => "error".to_string(),
+            LogLevel::Warning => "warn".to_string(),
+            LogLevel::Info => "info".to_string(),
+            LogLevel::Debug => "debug".to_string(),
+            LogLevel::Trace => "trace".to_string(),
+        }
+    }
+
+    fn string_to_log_level(level_str: &str) -> LogLevel {
+        match level_str.to_lowercase().as_str() {
+            "off" | "disabled" => LogLevel::Disabled,
+            "error" => LogLevel::Error,
+            "warn" | "warning" => LogLevel::Warning,
+            "info" => LogLevel::Info,
+            "debug" => LogLevel::Debug,
+            "trace" => LogLevel::Trace,
+            _ => LogLevel::Info, // 默认为 Info 级别
+        }
+    }
+}
+
+#[async_trait::async_trait]
+impl LoggerRpc for LoggerRpcService {
+    type Controller = BaseController;
+
+    async fn set_logger_config(
+        &self,
+        _: BaseController,
+        request: SetLoggerConfigRequest,
+    ) -> Result<SetLoggerConfigResponse, rpc_types::error::Error> {
+        let level_str = Self::log_level_to_string(request.level());
+
+        // 更新当前日志级别
+        if let Some(current_level) = CURRENT_LOG_LEVEL.get() {
+            if let Ok(mut level) = current_level.lock() {
+                *level = level_str.clone();
+            }
+        }
+
+        // 发送新的日志级别到 logger 重载器
+        if let Some(sender) = LOGGER_LEVEL_SENDER.get() {
+            if let Ok(sender) = sender.lock() {
+                if let Err(e) = sender.send(level_str) {
+                    tracing::warn!("Failed to send new log level to reloader: {}", e);
+                    return Err(rpc_types::error::Error::ExecutionError(anyhow::anyhow!(
+                        "Failed to update log level: {}",
+                        e
+                    )));
+                }
+            } else {
+                return Err(rpc_types::error::Error::ExecutionError(anyhow::anyhow!(
+                    "Logger sender is not available"
+                )));
+            }
+        } else {
+            return Err(rpc_types::error::Error::ExecutionError(anyhow::anyhow!(
+                "Logger reloader is not initialized"
+            )));
+        }
+
+        Ok(SetLoggerConfigResponse {})
+    }
+
+    async fn get_logger_config(
+        &self,
+        _: BaseController,
+        _request: GetLoggerConfigRequest,
+    ) -> Result<GetLoggerConfigResponse, rpc_types::error::Error> {
+        let current_level_str = if let Some(current_level) = CURRENT_LOG_LEVEL.get() {
+            if let Ok(level) = current_level.lock() {
+                level.clone()
+            } else {
+                "info".to_string() // 默认级别
+            }
+        } else {
+            "info".to_string() // 默认级别
+        };
+
+        let level = Self::string_to_log_level(&current_level_str);
+
+        Ok(GetLoggerConfigResponse {
+            level: level.into(),
+        })
+    }
+}