Judge: add seed (reproducible output) + interrupt support

New 'seed' input seeds sampling (torch.manual_seed before generation) so a fixed seed
reproduces the same output — no reroll when re-queueing while tweaking downstream nodes;
bump it to reroll (named 'seed' so the frontend adds control_after_generate). Generation
now honors ComfyUI cancel: a StoppingCriteria halts model.generate() promptly and
_check_interrupt() raises between passes. Workflows updated with the seed widget.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

workflow/workflow_ltx_audio_api.json

@@ -63,7 +63,8 @@
       "user_prompt": [
         "2",
         1
-      ]
+      ],
+      "seed": 0
     },
     "_meta": {
       "title": "Judge (chat + json_output) -> LTX beats JSON"