feat: GPU rendering + material matching + perf improvements

- GPU: fix Cycles device activation order — set compute_device_type
  BEFORE engine init, re-set AFTER open_mainfile wipes preferences
- GPU: remove _mark_sharp_and_seams edit-mode loop (redundant with
  Blender 5.0 shade_smooth_by_angle), saves ~200s/render on 175 parts
- Material: fix _AFN suffix mismatch — build AF-stripped mat_map keys
  and add prefix fallback in _apply_material_library (blender_render.py)
- Material: production GLB now uses get_material_library_path() which
  checks active AssetLibrary instead of empty legacy system setting
- Admin: RenderTemplateTable multi-select output types (M2M frontend)
- Admin: MaterialLibraryPanel replaced with link to Asset Libraries
- UX: move Toaster to top-left to avoid dispatch button overlap
- SQLAlchemy: add .unique() to all RenderTemplate M2M collection queries
- Logging: flush=True on all Blender progress prints, stdout reconfigure

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

frontend/src/pages/WorkflowEditor.tsx

@@ -389,10 +389,11 @@ function NewWorkflowModal({ onClose, onCreate, isLoading }: NewWorkflowModalProp
             <label className="block text-sm text-content-secondary mb-1">Typ</label>
             <div className="grid grid-cols-2 gap-2">
               {([
-                { value: 'still', label: 'Still', desc: 'Einzelbild PNG' },
-                { value: 'turntable', label: 'Turntable', desc: 'Animations-MP4' },
-                { value: 'multi_angle', label: 'Multi-Angle', desc: 'Mehrere Winkel' },
-                { value: 'custom', label: 'Custom', desc: 'Freier Editor' },
+                { value: 'still', label: 'Still', desc: 'Single PNG image' },
+                { value: 'turntable', label: 'Turntable', desc: 'Animation MP4' },
+                { value: 'multi_angle', label: 'Multi-Angle', desc: 'Multiple angles' },
+                { value: 'still_with_exports', label: 'Still + GLB', desc: 'PNG + GLB exports' },
+                { value: 'custom', label: 'Custom', desc: 'Free canvas' },
               ] as { value: WorkflowConfig['type']; label: string; desc: string }[]).map(opt => (
                 <button
                   key={opt.value}
@@ -650,6 +651,7 @@ export default function WorkflowEditor() {
     still: 'Still',
     turntable: 'Turntable',
     multi_angle: 'Multi-Angle',
+    still_with_exports: 'Still + GLB',
     custom: 'Custom',
   }
 
@@ -657,6 +659,7 @@ export default function WorkflowEditor() {
     still: 'bg-orange-100 text-orange-700 dark:bg-orange-900/40 dark:text-orange-300',
     turntable: 'bg-purple-100 text-purple-700 dark:bg-purple-900/40 dark:text-purple-300',
     multi_angle: 'bg-blue-100 text-blue-700 dark:bg-blue-900/40 dark:text-blue-300',
+    still_with_exports: 'bg-green-100 text-green-700 dark:bg-green-900/40 dark:text-green-300',
     custom: 'bg-surface-hover text-content-muted',
   }