Fix Generate click never reaching server: watchdog broke the click event

Confirmed via server logs (hf spaces logs) that after the previous fix
(8ed76c6), clicking Generate produced zero server-side activity across
all three tabs — none of _run_taro/_run_mmaudio/_run_hunyuan's print
statements ever appeared, meaning the click never even reached the
backend. Root cause: combining js= and a real server fn= on the same
.click() event (as 8ed76c6 did) is a combination that breaks the click
from firing at all, contrary to what the docs implied.

Fix: stop using Gradio's js= event-chaining for the watchdog entirely.
Arm it instead via a plain native document click listener (event
delegation, so it works regardless of when Svelte creates the button
DOM). The .click() chains are back to their pre-8ed76c6 form, which
was already confirmed working for triggering generation.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app.py

@@ -2687,6 +2687,18 @@ _GLOBAL_JS = """
     }, timeoutMs);
   };
 
+  // Arm the watchdog via a plain native click listener (event delegation on
+  // document, so it works regardless of when Gradio/Svelte creates the button
+  // elements) rather than Gradio's own js= event-chaining mechanism. Combining
+  // js= with a real server fn= on the SAME .click() event was tried and broke
+  // the click from ever reaching the server at all (confirmed via server logs
+  // showing zero activity after the click) — this sidesteps Gradio's event
+  // wiring entirely so it can't interfere with the real click → fn chain.
+  document.addEventListener('click', function(ev) {
+    const hit = ev.target.closest && ev.target.closest('#taro_btn, #mma_btn, #hf_btn');
+    if (hit) window._armGenerateWatchdog(hit.id, 600000);
+  });
+
   // ── ZeroGPU quota attribution ──
   // HF Spaces run inside an iframe on huggingface.co. Gradio's own JS client
   // gets ZeroGPU auth headers (x-zerogpu-token, x-zerogpu-uuid) by sending a
@@ -3161,7 +3173,6 @@ with gr.Blocks(title="Generate Audio for Video", css=_SLOT_CSS, js=_GLOBAL_JS) a
                 fn=_btn_generating,
                 inputs=None,
                 outputs=[taro_btn],
-                js="() => { window._armGenerateWatchdog('taro_btn', 600000); }",
             ).then(
                 fn=_run_taro,
                 inputs=[taro_video, taro_seed, taro_cfg, taro_steps, taro_mode,
@@ -3228,7 +3239,6 @@ with gr.Blocks(title="Generate Audio for Video", css=_SLOT_CSS, js=_GLOBAL_JS) a
                 fn=_btn_generating,
                 inputs=None,
                 outputs=[mma_btn],
-                js="() => { window._armGenerateWatchdog('mma_btn', 600000); }",
             ).then(
                 fn=_run_mmaudio,
                 inputs=[mma_video, mma_prompt, mma_neg, mma_seed,
@@ -3294,7 +3304,6 @@ with gr.Blocks(title="Generate Audio for Video", css=_SLOT_CSS, js=_GLOBAL_JS) a
                 fn=_btn_generating,
                 inputs=None,
                 outputs=[hf_btn],
-                js="() => { window._armGenerateWatchdog('hf_btn', 600000); }",
             ).then(
                 fn=_run_hunyuan,
                 inputs=[hf_video, hf_prompt, hf_neg, hf_seed,