submit: drop the agree checkbox, meta.json is the only consent gate

The Submit tab had both an "I agree" checkbox and required
meta.json to carry "agree_to_publish": true. Two gates expressing
the same intent, neither covering a case the other didn't, and
the UI half doesn't extend to programmatic submitters
(gradio_client, future REST API).

Drop the UI checkbox. meta.json["agree_to_publish"] stays the
single consent gate, uniform across browser + programmatic
submission. handle_submit signature shrinks to (zip_file).

Submit form is now: zip upload + Submit button.

app.py

@@ -75,19 +75,16 @@ and stripped to a single line. Shown in the per-submission detail view,
 not in the main leaderboard table.
 
 All five fields come from `meta.json` inside the zip, no separate
-form to fill in. The agree-checkbox below is the in-UI confirmation
-on top of `meta.json`'s `agree_to_publish: true`.
+form to fill in. Setting `agree_to_publish: true` in `meta.json` is
+your consent to publish on the public leaderboard.
 """
         )
         zip_in = gr.File(label="Submission ZIP", file_types=[".zip"])
-        agree_in = gr.Checkbox(
-            label="I agree to publish this result on the public leaderboard."
-        )
         submit_btn = gr.Button("Submit", variant="primary")
         submit_out = gr.Markdown()
         submit_btn.click(
             fn=handle_submit,
-            inputs=[zip_in, agree_in],
+            inputs=[zip_in],
             outputs=submit_out,
         )
 

submit.py

@@ -9,14 +9,13 @@ forever until later chunks add the background thread.
 
 Validation gates, in order:
 
-1. Form-level: a file was attached, the agree checkbox is ticked.
+1. Form-level: a file was attached.
 2. Zip safety: parseable as a zip, no absolute / parent-traversing
    entry names, no symlinks.
 3. ``meta.json`` schema: required keys present, types sane,
-   ``agree_to_publish`` is literally ``true``, ``notes`` is non-empty
-   when present and within the per-submission cap. Single source of
-   truth for submitter / submission identity; the Gradio form only
-   carries the zip and the in-UI agree checkbox.
+   ``agree_to_publish`` is literally ``true`` (the sole consent
+   gate; no separate UI checkbox), ``notes`` is non-empty when
+   present and within the per-submission cap.
 4. Fixture-set match: the set of folders inside the zip equals the
    set of fixture directories in :func:`cadgenbench.common.paths.data_inputs_dir`
    (no missing, no extras).
@@ -93,19 +92,19 @@ class _HubWriteError(Exception):
     """Raised when a Hub upload fails after validation succeeded."""
 
 
-def handle_submit(zip_file, agree: bool) -> str:
+def handle_submit(zip_file) -> str:
     """Validate a submission upload and return a markdown UI message.
 
     Returns one of:
       - An error string starting with ``**Error:**`` for form-level
-        rejects (missing zip, unticked agree box).
+        rejects (no zip attached).
       - A rejection string starting with ``**Submission rejected.**``
         for any of the deeper validation gates or Hub-write failures.
       - A success string starting with ``**Queued.**`` carrying the
         minted ``submission_id`` once the pending row + zip are on
         the Hub.
     """
-    form_err = _validate_form(zip_file, agree)
+    form_err = _validate_form(zip_file)
     if form_err is not None:
         return form_err
 
@@ -140,11 +139,9 @@ def handle_submit(zip_file, agree: bool) -> str:
     )
 
 
-def _validate_form(zip_file, agree: bool) -> str | None:
+def _validate_form(zip_file) -> str | None:
     if zip_file is None:
         return "**Error:** please attach a submission zip."
-    if not agree:
-        return "**Error:** you must agree to publish before submitting."
     return None