PhaseG3_register: 适配器注册到Host，全链路编译通过

gateway/src/IntegrationGateway.Host/Program.cs

@@ -30,8 +30,27 @@ var volProUrl = gwCfg["VolProBaseUrl"] ?? "http://localhost:9100";
 var httpFactory = app.Services.GetRequiredService<IHttpClientFactory>();
 var clientFactory = new GatewayClientFactory(httpFactory, volProUrl);
 
-// 适配器将在 Phase G2/G3 注册，此处预留
-Console.WriteLine("[Gateway] AdapterRegistry initialized, awaiting adapters...");
+// 注册 OwlAdapter
+var owlHttp = app.Services.GetRequiredService<IHttpClientFactory>().CreateClient("VolPro");
+var owlAdapter = new IntegrationGateway.Adapters.Owl.OwlAdapter(
+    "Owl:main", owlHttp,
+    owlCfg["BaseUrl"] ?? "http://localhost:15123",
+    owlCfg["Username"] ?? "admin",
+    owlCfg["Password"] ?? "admin"
+);
+registry.Register(owlAdapter);
+
+// 注册 MC4Adapter
+var mc4Http = app.Services.GetRequiredService<IHttpClientFactory>().CreateClient("VolPro");
+var mc4Adapter = new IntegrationGateway.Adapters.MC4.Mc4Adapter(
+    "MC4:31ku", mc4Http,
+    mc4Cfg["BaseUrl"] ?? "http://localhost:3000"
+);
+registry.Register(mc4Adapter);
+
+// 并行初始化适配器
+await registry.InitializeAllAsync();
+Console.WriteLine($"[Gateway] {registry.All.Count} adapter(s) registered");
 
 // ═══ B 组路由 ═══