refactor: rename thumbnail_rendering queue to asset_pipeline

The queue handles far more than thumbnails: OCC tessellation, USD master
generation, GLB production, order line renders, and workflow renders.
asset_pipeline better reflects its role as the render-worker's primary queue.

Updated all references in: task decorators, celery_app.py, beat_tasks.py,
docker-compose.yml worker command, worker.py MONITORED_QUEUES, admin.py,
CLAUDE.md, LEARNINGS.md, Dockerfile, helpTexts.ts, test files,
and all .claude/commands/*.md skill files.

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

backend/app/tasks/beat_tasks.py

@@ -73,7 +73,7 @@ def broadcast_queue_status() -> None:
         r = sync_redis.from_url(settings.redis_url, decode_responses=True)
         depths = {
             "step_processing": r.llen("step_processing"),
-            "thumbnail_rendering": r.llen("thumbnail_rendering"),
+            "asset_pipeline": r.llen("asset_pipeline"),
         }
         event = {"type": "queue_update", "depths": depths}
         r.publish("__broadcast__", json.dumps(event))

backend/app/tasks/celery_app.py

@@ -30,7 +30,7 @@ celery_app.conf.update(
     enable_utc=True,
     task_routes={
         "app.domains.pipeline.tasks.*": {"queue": "step_processing"},
-        "app.domains.rendering.tasks.*": {"queue": "thumbnail_rendering"},
+        "app.domains.rendering.tasks.*": {"queue": "asset_pipeline"},
         "app.tasks.beat_tasks.*": {"queue": "step_processing"},
         "app.tasks.ai_tasks.*": {"queue": "ai_validation"},
         # Legacy task names (shim) — keep until old queued tasks drain

backend/app/tasks/gpu_tasks.py

@@ -5,7 +5,7 @@ from app.tasks.celery_app import celery_app
 logger = logging.getLogger(__name__)
 
 
-@celery_app.task(name="app.tasks.gpu_tasks.probe_gpu", queue="thumbnail_rendering")
+@celery_app.task(name="app.tasks.gpu_tasks.probe_gpu", queue="asset_pipeline")
 def probe_gpu() -> dict:
     """Run Blender GPU probe on the render-worker. Stores result in system_settings."""
     import subprocess