chore: remove temporary moderate_debug tuning endpoint

Rubric tuning showed the current MODERATION_PROMPT reliably rates clear genitals
as 4_EXPLICIT_SEXUAL; no candidate improved it, so the debug scaffold is removed
and the gemma4 rubric kept as-is.

app.py

@@ -573,13 +573,13 @@ def _parse_moderation_json(text):
     return {"ok": False, "rating": None, "confidence": None, "flags": None, "raw": raw}
 
 
-def _moderate_image_inner(image, max_new_tokens=320, prompt=None):
+def _moderate_image_inner(image, max_new_tokens=320):
     """Synchronously run the VLM moderation check on a PIL image (GPU-side)."""
     messages = [{
         "role": "user",
         "content": [
             {"type": "image", "image": image},
-            {"type": "text", "text": prompt or MODERATION_PROMPT},
+            {"type": "text", "text": MODERATION_PROMPT},
         ],
     }]
     inputs = vlm_processor.apply_chat_template(
@@ -1160,23 +1160,6 @@ def _image_video_check_gpu(image, message, reasoning, max_new_tokens, system_pro
     yield from _vlm_chat_core(message, image, reasoning, max_new_tokens, system_prompt)
 
 
-# --- TEMP moderation-prompt tuning endpoint (remove once rubric is finalized) ---
-@spaces.GPU
-def _moderate_debug_gpu(image, prompt_text=""):
-    """Run the exact moderation inference with a caller-supplied prompt so the
-    rubric can be tuned against fixed images via the real GPU path."""
-    return _moderate_image_inner(image, prompt=(prompt_text or None))
-
-
-def moderate_debug(image, prompt_text="", progress=gr.Progress(track_tqdm=True)):
-    if image is None:
-        return {"error": "no image"}
-    try:
-        return _moderate_debug_gpu(image, prompt_text)
-    except Exception as exc:  # noqa: BLE001
-        return {"error": f"{type(exc).__name__}: {exc}"}
-
-
 def generate_and_upload(
     model_name,
     prompt,
@@ -1859,17 +1842,6 @@ with gr.Blocks(fill_height=True) as demo:
         api_name="image_to_video_assets",
     )
 
-    # TEMP: moderation-prompt tuning endpoint (remove once rubric is finalized).
-    with gr.Row(visible=False):
-        mdbg_image = gr.Image(label="mdbg image", type="pil")
-        mdbg_prompt = gr.Textbox(label="mdbg prompt", value="")
-        mdbg_btn = gr.Button("mdbg", visible=False)
-        mdbg_out = gr.JSON(label="mdbg out")
-    mdbg_btn.click(
-        fn=moderate_debug, inputs=[mdbg_image, mdbg_prompt], outputs=[mdbg_out],
-        api_name="moderate_debug",
-    )
-
     # UI-less combined endpoint: text -> first-frame image (R2) + video prompt.
     # `gr.api` derives its schema from the function's type hints and registers no
     # components, so it adds an API route without touching the visible UI.