Move css and head back to gr.Blocks() for Gradio 5 compat

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app.py

@@ -309,6 +309,8 @@ _CSS = ".error-box { background: #fee; border: 1px solid #c00; border-radius: 8p
 
 with gr.Blocks(
     title="everyrow annotate – AI Data Annotation & Web Research",
+    css=_CSS,
+    head=POSTHOG_HEAD,
 ) as demo:
     gr.Markdown(
         """
@@ -636,4 +638,4 @@ with gr.Blocks(
     )
 
 if __name__ == "__main__":
-    demo.launch(css=_CSS, head=POSTHOG_HEAD)
+    demo.launch()