feat: 插件自动挂载测试机制 — capabilities + self_test + 3阶段启动

- Plugin trait 增加 capabilities() 和 self_test() 方法
- PluginVTable 增加 get_capabilities 和 self_test FFI
- ServiceManager 三阶段启动: init → self_test → start
- SendCallback 改为 ctx 参数传递，消除 thread_local
- export_plugin! 宏所有 FFI 函数包裹 catch_unwind
- PluginManifest 增加 capabilities/required_capabilities/auto_test
- 新增 3 个自测相关测试用例 (共 59 测试)

src/core/plugin_loader.rs

@@ -29,12 +29,28 @@ pub struct PluginManifest {
     #[serde(default = "default_error_policy")]
     pub error_policy: ErrorPolicy,
     pub so_filename: String,
+    /// 插件声明支持的功能列表
+    #[serde(default)]
+    pub capabilities: Vec<String>,
+    /// 挂载时必须通过测试的功能（capabilities 的子集）
+    #[serde(default)]
+    pub required_capabilities: Vec<String>,
+    /// 自测超时（毫秒），默认 5000
+    #[serde(default = "default_test_timeout")]
+    pub test_timeout_ms: u64,
+    /// 是否在挂载时自动运行自测，默认 true
+    #[serde(default = "default_true")]
+    pub auto_test: bool,
 }
 
 fn default_error_policy() -> ErrorPolicy {
     ErrorPolicy::AutoRollback
 }
 
+fn default_test_timeout() -> u64 {
+    5000
+}
+
 /// 插件错误处理策略
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
 #[serde(rename_all = "snake_case")]
@@ -250,6 +266,10 @@ mod tests {
             dependencies: vec![],
             error_policy: ErrorPolicy::AutoRollback,
             so_filename: "libtest_plugin.so".to_string(),
+            capabilities: vec![],
+            required_capabilities: vec![],
+            test_timeout_ms: 5000,
+            auto_test: true,
         };
 
         fs::write(
@@ -333,4 +353,38 @@ mod tests {
 
         let _ = fs::remove_dir_all(&tmp);
     }
+
+    #[test]
+    fn manifest_parses_capabilities() {
+        let json = r#"{
+            "id": "sensor",
+            "version": "1.0.0",
+            "sdk_version": "0.2.0",
+            "so_filename": "libsensor.so",
+            "capabilities": ["temperature", "humidity"],
+            "required_capabilities": ["temperature"],
+            "test_timeout_ms": 3000,
+            "auto_test": true
+        }"#;
+        let manifest: PluginManifest = serde_json::from_str(json).unwrap();
+        assert_eq!(manifest.capabilities, vec!["temperature", "humidity"]);
+        assert_eq!(manifest.required_capabilities, vec!["temperature"]);
+        assert_eq!(manifest.test_timeout_ms, 3000);
+        assert!(manifest.auto_test);
+    }
+
+    #[test]
+    fn manifest_capabilities_default_empty() {
+        let json = r#"{
+            "id": "basic",
+            "version": "1.0.0",
+            "sdk_version": "0.2.0",
+            "so_filename": "libbasic.so"
+        }"#;
+        let manifest: PluginManifest = serde_json::from_str(json).unwrap();
+        assert!(manifest.capabilities.is_empty());
+        assert!(manifest.required_capabilities.is_empty());
+        assert_eq!(manifest.test_timeout_ms, 5000);
+        assert!(manifest.auto_test);
+    }
 }