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>

scripts/test_render_pipeline.py

@@ -125,7 +125,7 @@ def test_health(client: APIClient) -> bool:
     info(f"Overall status: {data['status']}")
     info(f"Render worker connected: {data['render_worker_connected']}")
     info(f"Blender available: {data['blender_available']}")
-    info(f"thumbnail_rendering queue depth: {data['thumbnail_queue_depth']}")
+    info(f"asset_pipeline queue depth: {data['thumbnail_queue_depth']}")
     if data.get("last_render_at"):
         info(f"Last render: {data['last_render_at']} ({'success' if data['last_render_success'] else 'FAILED'}, {data['last_render_age_minutes']}m ago)")
 
@@ -140,9 +140,9 @@ def test_health(client: APIClient) -> bool:
         fail("Blender renderer NOT reachable — thumbnail/order renders will fail")
 
     if data["thumbnail_queue_ok"]:
-        ok(f"thumbnail_rendering queue healthy (depth={data['thumbnail_queue_depth']})")
+        ok(f"asset_pipeline queue healthy (depth={data['thumbnail_queue_depth']})")
     else:
-        warn(f"thumbnail_rendering queue DEEP ({data['thumbnail_queue_depth']} tasks) — renders may be slow")
+        warn(f"asset_pipeline queue DEEP ({data['thumbnail_queue_depth']} tasks) — renders may be slow")
 
     return data["status"] != "down"