fix(shader): Use custom_background callback to render blurred texture

- Add _render_custom_background method as hello_imgui callback
- Render blurred FBO texture as ImGui background
- Use ctypes.cast to convert OpenGL texture ID to ImTextureRef

config.toml

@@ -56,7 +56,7 @@ Response = true
 Theme = true
 "Log Management" = true
 Diagnostics = false
-"External Tools" = true
+"External Tools" = false
 "Shader Editor" = true
 
 [theme]
@@ -64,8 +64,8 @@ palette = "Nord Dark"
 font_path = "C:/projects/manual_slop/assets/fonts/MapleMono-Regular.ttf"
 font_size = 18.0
 scale = 1.0
-transparency = 0.5400000214576721
-child_transparency = 1.0
+transparency = 0.4399999976158142
+child_transparency = 0.5099999904632568
 
 [mma]
 max_workers = 4