Fix G-Code upload spinner by keeping file widget always mounted

app.py

@@ -330,7 +330,7 @@ GCODE_SOURCE_UPLOAD = "Upload G-Code file"
 
 
 def toggle_gcode_source(source: str) -> dict[str, Any]:
-    return gr.update(visible=(source == GCODE_SOURCE_UPLOAD))
+    return gr.update(interactive=(source == GCODE_SOURCE_UPLOAD))
 
 
 def render_toolpath(
@@ -666,7 +666,7 @@ def build_demo() -> gr.Blocks:
                 gcode_upload = gr.File(
                     label="Upload G-Code",
                     file_types=[".txt", ".gcode", ".nc"],
-                    visible=False,
+                    interactive=False,
                 )
             render_button = gr.Button("Render Tool Path", variant="primary")
             toolpath_plot = gr.Plot(label="Tool Path")
@@ -676,6 +676,7 @@ def build_demo() -> gr.Blocks:
                 fn=toggle_gcode_source,
                 inputs=[gcode_source],
                 outputs=[gcode_upload],
+                queue=False,
             )
             render_button.click(
                 fn=render_toolpath,