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/worker.py

@@ -237,7 +237,7 @@ async def reprocess_cad_file(
 # Queue inspection + control
 # ---------------------------------------------------------------------------
 
-MONITORED_QUEUES = ["step_processing", "thumbnail_rendering", "ai_validation"]
+MONITORED_QUEUES = ["step_processing", "asset_pipeline", "ai_validation"]
 
 
 def _parse_redis_task(raw: str) -> dict | None:
@@ -515,7 +515,7 @@ async def render_health(
 
     details: dict = {}
 
-    # 1. Check if render-worker (thumbnail_rendering queue) is connected + has Blender
+    # 1. Check if render-worker (asset_pipeline queue) is connected + has Blender
     render_worker_connected = False
     blender_available = False
 
@@ -534,10 +534,10 @@ async def render_health(
     else:
         all_workers = list(inspect_result.get("ping", {}).keys())
         details["workers"] = all_workers
-        # Find any worker consuming thumbnail_rendering queue
+        # Find any worker consuming asset_pipeline queue
         for worker_name, queues in inspect_result.get("active_queues", {}).items():
             queue_names = [q.get("name") for q in (queues or [])]
-            if "thumbnail_rendering" in queue_names:
+            if "asset_pipeline" in queue_names:
                 render_worker_connected = True
                 # render-worker always has Blender — it starts Blender successfully
                 blender_available = True
@@ -547,11 +547,11 @@ async def render_health(
             render_worker_connected = True
             details["worker_detection"] = "fallback"
 
-    # 3. Queue depth for thumbnail_rendering
+    # 3. Queue depth for asset_pipeline
     thumbnail_queue_depth = 0
     try:
         r = redis_lib.from_url(app_settings.redis_url, decode_responses=True)
-        thumbnail_queue_depth = r.llen("thumbnail_rendering") or 0
+        thumbnail_queue_depth = r.llen("asset_pipeline") or 0
     except Exception as exc:
         details["redis_error"] = str(exc)