fix: move css to launch() per Gradio 6.x deprecation

app.py

@@ -602,7 +602,7 @@ def modal_health_handler():
 initial_operator_state = _default_operator_state()
 initial_regions = _dashboard_regions(scan=scan_file(None), operator_state=initial_operator_state)
 
-with gr.Blocks(title="NEXUS Visual Weaver", css=APP_CSS) as demo:
+with gr.Blocks(title="NEXUS Visual Weaver") as demo:
     active_run_state = gr.State(None)
     scan_state = gr.State(scan_file(None))
     operator_state = gr.State(initial_operator_state)
@@ -846,4 +846,5 @@ if __name__ == "__main__":
         server_name="0.0.0.0",
         server_port=int(os.environ.get("NEXUS_PORT", os.environ.get("PORT", "7860"))),
         quiet=True, mcp_server=True, ssr_mode=False,
+        css=APP_CSS,
     )