Fix string formatting in Blender script template

- Changed f-strings to string concatenation in GPU config section
- Fixes KeyError: 'compute_device_type' in .format() call
- Aligns with demo.zip coding style (string concatenation, not f-strings)
- Lines 374, 382, 384: Removed f-string syntax to avoid format() conflicts

code/cube3d/render/render_bricks_safe.py

@@ -371,7 +371,7 @@ try:
             if device['name'].startswith(('NVIDIA', 'Apple', 'AMD')):
                 device['use'] = 1
                 gpu_used = True
-                print(f"✅ 启用 GPU: {{device['name']}}")
+                print("✅ 启用 GPU: " + device['name'])
             else:
                 device['use'] = 0
         if not gpu_used:
@@ -379,9 +379,9 @@ try:
             scene.cycles.device = 'CPU'
             print("ℹ️  使用 CPU 渲染（samples=512）")
         else:
-            print(f"ℹ️  使用 GPU 渲染（{compute_device_type}, samples=512）")
+            print("ℹ️  使用 GPU 渲染（" + compute_device_type + ", samples=512）")
     except Exception as gpu_error:
-        print(f"⚠️  GPU 初始化失败: {{gpu_error}}")
+        print("⚠️  GPU 初始化失败: " + str(gpu_error))
         print("ℹ️  回退到 CPU 渲染（samples=512）")
         scene.cycles.device = 'CPU'