feat: 实现动态插件系统 (6阶段完成)

- 阶段1: 消息类型序列化 (Serialize/Deserialize, &'static str → String)
- 阶段2: FFI 边界类型 + Plugin SDK (plugin_abi, showen-plugin-sdk crate)
- 阶段3: PluginLoader + DynamicPlugin (libloading 动态加载 .so)
- 阶段4: 版本管理 + 错误策略 (VersionManager, PluginState, 自动回退)
- 阶段5: 远程仓库客户端 (HTTP 下载 + tar.gz 安装)
- 阶段6: 示例插件 + HTTP 管理 API + 全目录 README 文档

54/54 测试通过，0 warnings。

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/core/message.rs

@@ -1,19 +1,20 @@
 use crate::core::config::AppConfig;
+use serde::{Deserialize, Serialize};
 use std::sync::Arc;
 
 /// 消息信封：包含来源、目的地、消息体
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct Envelope {
-    pub from: &'static str,
+    pub from: String,
     pub to: Destination,
     pub message: Message,
 }
 
 /// 消息目的地
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub enum Destination {
     /// 点对点发送给指定插件
-    Plugin(&'static str),
+    Plugin(String),
     /// 广播给所有插件
     Broadcast,
     /// 发给管理层自身
@@ -21,7 +22,7 @@ pub enum Destination {
 }
 
 /// 所有插件间通信的类型安全消息
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub enum Message {
     // ── 播放控制 ──
     PlayerCommand(PlayerCommand),
@@ -48,12 +49,14 @@ pub enum Message {
     },
 
     // ── 配置 ──
+    /// Arc<AppConfig> 无法跨 FFI 序列化，动态插件通过 init 时传入的 JSON 获取配置
+    #[serde(skip)]
     ConfigReloaded(Arc<AppConfig>),
     ConfigReloadRequest,
 
     // ── 系统 ──
     Shutdown,
-    PluginReady(&'static str),
+    PluginReady(String),
 
     // ── 扩展（未来插件用） ──
     Custom {
@@ -62,7 +65,7 @@ pub enum Message {
     },
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub enum PlayerCommand {
     Play,
     Pause,
@@ -72,7 +75,7 @@ pub enum PlayerCommand {
     ChangeScene(String),
 }
 
-#[derive(Debug, Clone, serde::Serialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct PlayerStatusData {
     pub running: bool,
     pub paused: bool,
@@ -82,7 +85,7 @@ pub struct PlayerStatusData {
     pub current_video: Option<String>,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub enum WifiCommand {
     Scan,
     Connect { ssid: String, password: String },