fix: media thumbnails, product dimensions, inline 3D viewer, GLB export

Bug A: Media Library thumbnails were gray because <img src> cannot send
JWT auth headers. Added useAuthBlob() hook (fetch + createObjectURL) in
MediaBrowser.tsx. Also fixed publish_asset Celery task to populate
product_id + cad_file_id on MediaAsset for thumbnail fallback resolution.

Bug B: Product dimensions now shown in Product Details card with Ruler
icon and "from CAD" label when cad_mesh_attributes.dimensions_mm exists.

Bug C: Replaced 128×128 CAD thumbnail with InlineCadViewer component.
Queries gltf_geometry MediaAssets, fetches GLB via auth fetch → blob URL
→ Three.js Canvas with OrbitControls. Falls back to thumbnail + "Load 3D
Model" button. Polling when GLB generation is in progress.

Bug D: trimesh was in [cad] optional extra but Dockerfile only installed
[dev]. Changed to pip install -e ".[dev,cad]" — trimesh now available in
backend container, GLB + Colors export works.

Also added bbox extraction (STL-first numpy parsing) in render_step_thumbnail
and admin "Re-extract CAD Metadata" bulk endpoint.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/domains/media/service.py

@@ -5,6 +5,13 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.domains.media.models import MediaAsset, MediaAssetType
 
 
+_SORT_COLUMNS = {
+    "created_at": MediaAsset.created_at,
+    "file_size_bytes": MediaAsset.file_size_bytes,
+    "storage_key": MediaAsset.storage_key,
+}
+
+
 async def list_media_assets(
     db: AsyncSession,
     product_id: uuid.UUID | None = None,
@@ -15,8 +22,13 @@ async def list_media_assets(
     is_archived: bool | None = False,
     skip: int = 0,
     limit: int = 50,
+    sort_by: str = "created_at",
+    sort_dir: str = "desc",
 ) -> list[MediaAsset]:
-    q = select(MediaAsset).order_by(MediaAsset.created_at.desc())
+    from sqlalchemy import asc, desc
+    col = _SORT_COLUMNS.get(sort_by, MediaAsset.created_at)
+    order = desc(col) if sort_dir == "desc" else asc(col)
+    q = select(MediaAsset).order_by(order)
     if product_id:
         q = q.where(MediaAsset.product_id == product_id)
     if order_line_id: