Images no longer load textures eagerly on creation. Instead, the
culling ticker checks viewport proximity every 200ms:
- Load margin: 1x screen size beyond viewport (preload before visible)
- Unload margin: 2x screen size (hysteresis prevents thrash during pan)
ImageSprite changes:
- Constructor no longer calls loadTexture() — deferred to culling system
- New unloadTexture() restores placeholder and frees GPU memory
- Exposed texture getter for clipboard resolution detection
- loaded field now public for culling system to check state
This should allow hundreds of images without GPU OOM, since only
nearby textures consume GPU memory at any time.
Hiren Kangad
86024464c2