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>

frontend/src/api/orders.ts

@@ -276,6 +276,18 @@ export async function generateLinesFromItems(
   return res.data
 }
 
+export async function rejectOrderLine(
+  orderId: string,
+  lineId: string,
+  reason: string,
+): Promise<{ rejected: boolean; line_id: string; reason: string }> {
+  const res = await api.post<{ rejected: boolean; line_id: string; reason: string }>(
+    `/orders/${orderId}/lines/${lineId}/reject`,
+    { reason },
+  )
+  return res.data
+}
+
 export async function rejectOrder(orderId: string, reason: string, notifyClient: boolean = true): Promise<Order> {
   const res = await api.post<Order>(`/orders/${orderId}/reject`, {
     reason,