Mount Gradio UI at root path so HF Spaces iframe shows it

HF Docker Spaces iframe-load the container's root path (/). Our Gradio
UI was only mounted at /web, so the Space appeared blank. Keep /web for
backward compat with existing docs, also mount at / for HF.

Also drop the unsupported `base_path: /web` field from README frontmatter.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -6,7 +6,6 @@ colorTo: red
 sdk: docker
 pinned: false
 app_port: 8000
-base_path: /web
 tags:
   - openenv
 ---

server/app.py

@@ -22,9 +22,12 @@ if _enable_web:
     # Create the base API app (reset/step/state/health/schema endpoints)
     app = create_fastapi_app(CarromEnvironment, Action, Observation)
 
-    # Mount the custom Gradio UI
+    # Mount the custom Gradio UI at BOTH paths:
+    #   - "/"    so HF Spaces' root-path iframe loads the UI directly
+    #   - "/web" kept for backward compat with existing docs/links
     import gradio as gr
     app = gr.mount_gradio_app(app, _gradio_app, path="/web")
+    app = gr.mount_gradio_app(app, _gradio_app, path="/")
 else:
     app = create_app(
         CarromEnvironment,