test: 添加插件依赖机制自动化回归测试

- 新增 7 个测试用例固化插件依赖关系
- 验证 http 插件依赖 video
- 验证 ble/wifi/video/screen 插件无依赖
- 验证所有插件 ID 唯一性
- 验证拓扑排序正确性（依赖项先初始化）
- 所有 31 个测试通过

防止依赖关系漂移，确保架构稳定性。

src/core/tests.rs

@@ -319,3 +319,101 @@ fn wifi_result_sent_to_manager_is_broadcast_to_plugins() {
     assert!(has_event(&events, "msg:alpha:wifi_result:connected"));
     assert!(has_event(&events, "msg:beta:wifi_result:connected"));
 }
+
+#[test]
+fn http_plugin_must_depend_on_video() {
+    use crate::plugins::http::HttpPlugin;
+    let plugin = HttpPlugin::new();
+    let deps = plugin.dependencies();
+    assert_eq!(deps, vec!["video"], "http plugin must depend on video");
+}
+
+#[test]
+fn ble_plugin_must_have_no_dependencies() {
+    use crate::plugins::ble::BlePlugin;
+    let plugin = BlePlugin::new();
+    let deps = plugin.dependencies();
+    assert!(deps.is_empty(), "ble plugin must have no dependencies");
+}
+
+#[test]
+fn wifi_plugin_must_have_no_dependencies() {
+    use crate::plugins::wifi::WifiPlugin;
+    let plugin = WifiPlugin::new();
+    let deps = plugin.dependencies();
+    assert!(deps.is_empty(), "wifi plugin must have no dependencies");
+}
+
+#[test]
+fn video_plugin_must_have_no_dependencies() {
+    use crate::plugins::video::VideoPlugin;
+    let plugin = VideoPlugin::new();
+    let deps = plugin.dependencies();
+    assert!(deps.is_empty(), "video plugin must have no dependencies");
+}
+
+#[test]
+fn screen_plugin_must_have_no_dependencies() {
+    use crate::plugins::screen::ScreenPlugin;
+    let plugin = ScreenPlugin::new();
+    let deps = plugin.dependencies();
+    assert!(deps.is_empty(), "screen plugin must have no dependencies");
+}
+
+#[test]
+fn all_plugin_ids_must_be_unique() {
+    use crate::plugins::ble::BlePlugin;
+    use crate::plugins::http::HttpPlugin;
+    use crate::plugins::screen::ScreenPlugin;
+    use crate::plugins::video::VideoPlugin;
+    use crate::plugins::wifi::WifiPlugin;
+    use std::collections::HashSet;
+
+    let plugins: Vec<Box<dyn Plugin>> = vec![
+        Box::new(BlePlugin::new()),
+        Box::new(HttpPlugin::new()),
+        Box::new(ScreenPlugin::new()),
+        Box::new(VideoPlugin::new()),
+        Box::new(WifiPlugin::new()),
+    ];
+
+    let mut ids = HashSet::new();
+    for plugin in plugins {
+        let id = plugin.id();
+        assert!(ids.insert(id), "duplicate plugin id detected: '{}'", id);
+    }
+}
+
+#[test]
+fn topological_sort_places_http_after_video() {
+    let events = Arc::new(Mutex::new(Vec::new()));
+    let mut manager = ServiceManager::new(test_config());
+
+    manager.register(Box::new(TestPlugin::new(
+        "http",
+        vec!["video"],
+        events.clone(),
+    )));
+    manager.register(Box::new(TestPlugin::new("video", vec![], events.clone())));
+
+    manager
+        .start_all()
+        .expect("start_all should succeed with http depending on video");
+
+    let event_log = lock_events(&events).clone();
+    let http_init_pos = event_log
+        .iter()
+        .position(|e| e == "init:http")
+        .expect("http should be initialized");
+    let video_init_pos = event_log
+        .iter()
+        .position(|e| e == "init:video")
+        .expect("video should be initialized");
+
+    assert!(
+        video_init_pos < http_init_pos,
+        "video must be initialized before http (video at {}, http at {})",
+        video_init_pos,
+        http_init_pos
+    );
+}