refactor: remove dead export_gltf.py, cleanup rendering tasks, improve tessellation UI

- Remove export_gltf.py (Blender-based GLB export replaced by OCC direct)
- Remove unused export_gltf_for_order_line_task
- Add Ultra tessellation preset to Admin settings
- Improve tessellation preset descriptions and styling
- Minor cleanup across media, rendering, and workflow modules

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

backend/app/domains/media/models.py

@@ -14,8 +14,8 @@ class MediaAssetType(str, enum.Enum):
     turntable = "turntable"
     stl_low = "stl_low"
     stl_high = "stl_high"
-    gltf_geometry = "gltf_geometry"      # DEPRECATED: use usd_master — viewer GLB auto-generated as part of USD pipeline
-    gltf_production = "gltf_production"  # DEPRECATED: use usd_master — high-quality production GLB superseded by USD master
+    gltf_geometry = "gltf_geometry"
+    gltf_production = "gltf_production"  # LEGACY — kept for ORM compatibility with existing DB rows, no longer generated
     blend_production = "blend_production"
     usd_master = "usd_master"
 

backend/app/domains/media/router.py

@@ -142,7 +142,6 @@ async def browse_media_assets(
     # Apply filters
     _TECHNICAL_TYPES = (
         MediaAssetType.gltf_geometry,
-        MediaAssetType.gltf_production,
         MediaAssetType.blend_production,
         MediaAssetType.stl_low,
         MediaAssetType.stl_high,