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/rendering/dispatch_service.py

@@ -87,6 +87,30 @@ def dispatch_render_with_workflow(order_line_id: str) -> dict:
             workflow_type,
         )
 
+        # For turntable workflows: resolve step_path + output_dir from the order line at runtime
+        if workflow_type == "turntable" and ("step_path" not in params or "output_dir" not in params):
+            from app.domains.products.models import CadFile as _CadFile
+            from pathlib import Path as _Path
+            from app.config import settings as _cfg
+            _product = line.product if hasattr(line, "product") else None
+            if _product is None:
+                from sqlalchemy.orm import selectinload as _si
+                from app.domains.orders.models import OrderLine as _OL
+                _line_full = session.execute(
+                    select(_OL).where(_OL.id == line.id).options(_si(_OL.product))
+                ).scalar_one_or_none()
+                _product = _line_full.product if _line_full else None
+            if _product and _product.cad_file_id:
+                _cad = session.execute(
+                    select(_CadFile).where(_CadFile.id == _product.cad_file_id)
+                ).scalar_one_or_none()
+                if _cad and _cad.stored_path:
+                    params.setdefault("step_path", _cad.stored_path)
+                    params.setdefault(
+                        "output_dir",
+                        str(_Path(_cfg.upload_dir) / "renders" / str(line.id)),
+                    )
+
         from app.domains.rendering.workflow_builder import dispatch_workflow
         celery_task_id = dispatch_workflow(workflow_type, order_line_id, params)