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/api/routers/cad.py

@@ -1,4 +1,5 @@
 """CAD file router - serve thumbnails, glTF models, parsed objects, and trigger reprocessing."""
+import logging
 import uuid
 from datetime import datetime
 from pathlib import Path
@@ -20,6 +21,7 @@ from app.utils.auth import get_current_user, is_privileged
 from app.services.product_service import link_cad_to_product, lookup_product
 
 router = APIRouter(prefix="/cad", tags=["cad"])
+logger = logging.getLogger(__name__)
 
 
 # ---------------------------------------------------------------------------
@@ -273,6 +275,7 @@ async def get_objects(
         "cad_file_id": str(cad.id),
         "original_name": cad.original_name,
         "processing_status": cad.processing_status.value,
+        "step_hash": cad.step_file_hash,
         "parsed_objects": cad.parsed_objects,
     }
 
@@ -318,6 +321,11 @@ async def generate_gltf_production(
     if not cad.stored_path:
         raise HTTPException(status_code=404, detail="STEP file not uploaded for this CAD file")
 
+    logger.warning(
+        "generate_gltf_production called for cad %s — "
+        "deprecated: renders now consume usd_master directly",
+        id,
+    )
     from app.tasks.step_tasks import generate_gltf_production_task
     task = generate_gltf_production_task.delay(str(id))
     return {"status": "queued", "task_id": task.id, "cad_file_id": str(id)}