[diffusion] app: support webui (#14961)

Co-authored-by: Mick <mickjagger19@icloud.com>

python/sglang/multimodal_gen/runtime/server_args.py

@@ -295,6 +295,10 @@ class ServerArgs:
     host: str | None = None
     port: int | None = None
 
+    # TODO: webui and their endpoint, check if webui_port is available.
+    webui: bool = False
+    webui_port: int | None = 12312
+
     scheduler_port: int = 5555
 
     # Stage verification
@@ -613,6 +617,19 @@ class ServerArgs:
             default=ServerArgs.port,
             help="Port for the HTTP API server.",
         )
+        parser.add_argument(
+            "--webui",
+            action=StoreBoolean,
+            default=ServerArgs.webui,
+            help="Whether to use webui for better display",
+        )
+
+        parser.add_argument(
+            "--webui-port",
+            type=int,
+            default=ServerArgs.webui_port,
+            help="Whether to use webui for better display",
+        )
 
         # Stage verification
         parser.add_argument(