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/domains/pipeline/tasks/render_thumbnail.py

@@ -14,11 +14,11 @@ from app.core.pipeline_logger import PipelineLogger
 logger = logging.getLogger(__name__)
 
 
-@celery_app.task(bind=True, name="app.tasks.step_tasks.render_step_thumbnail", queue="thumbnail_rendering")
+@celery_app.task(bind=True, name="app.tasks.step_tasks.render_step_thumbnail", queue="asset_pipeline")
 def render_step_thumbnail(self, cad_file_id: str):
     """Render the thumbnail for a freshly-processed STEP file.
 
-    Runs on the dedicated thumbnail_rendering queue (concurrency=1) so the
+    Runs on the dedicated asset_pipeline queue (concurrency=1) so the
     blender-renderer service is never overwhelmed by concurrent requests.
     On success, also auto-populates materials and marks the CadFile as completed.
     """
@@ -139,7 +139,7 @@ def render_step_thumbnail(self, cad_file_id: str):
     # Auto-populate materials now that parsed_objects are available
     try:
         from app.domains.pipeline.tasks.extract_metadata import _auto_populate_materials_for_cad
-        _auto_populate_materials_for_cad(cad_file_id)
+        _auto_populate_materials_for_cad(cad_file_id, tenant_id=_tenant_id)
     except Exception:
         logger.exception(
             f"Auto material population failed for cad_file {cad_file_id} (non-fatal)"
@@ -180,7 +180,7 @@ def render_step_thumbnail(self, cad_file_id: str):
     pl.step_done("render_step_thumbnail")
 
 
-@celery_app.task(bind=True, name="app.tasks.step_tasks.regenerate_thumbnail", queue="thumbnail_rendering")
+@celery_app.task(bind=True, name="app.tasks.step_tasks.regenerate_thumbnail", queue="asset_pipeline")
 def regenerate_thumbnail(self, cad_file_id: str, part_colors: dict):
     """Regenerate thumbnail with per-part colours."""
     pl = PipelineLogger(task_id=self.request.id)