Remove unused assets
Deleted 107 unused asset files and their .import sidecars across:
- gardens/gardens: all 20 _locked background variants (only _open is loaded dynamically)
- lesson_screen: old/removed UI images (_old files, button states replaced by theme SVGs)
- look_and_learn: removed UI elements (cubes, grids, masks, tracing bg, old fx)
- menus: 4 unused checkbox images
- minigames/boss: friends.png
- minigames/caterpillar: berry_bue.png (unused typo), caterpillar_tail.png
- minigames/crabs: halo_2.png, success_2.png
- minigames/frog: void.png, white.png
- minigames/monkeys/audio: monkey_random_01-03.mp3, monkey_receiveheadcoco.mp3
- minigames/minigame_ui: 24 unused button states (cancel, energy, next, ok, toy_chest, etc.)
- sfx: blast_1-5.mp3, fireworks_1-5.mp3 (fireworks is visual-only), unused UI sounds
- vfx: collectibles_spritesheet, cross, dustparticule, explosion_spritesheet, fx_03-08, sparkles
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Adrien Ufferte
6717e46d3a