fix: reduce startup heap usage

[mattrossman]

• Replaces BitmapLayer objects with direct graphics_draw_bitmap_in_rect calls
• Replaces TextLayer objects with direct graphics_draw_text calls
• Decouples memory debug logging from dev profile, instead use ENABLE_MEMORY_LOGGING=1 in .env

Refs:

• https://developer.rebble.io/docs/c/User_Interface/Layers/BitmapLayer/
• https://developer.rebble.io/docs/c/Graphics/Drawing_Primitives/#graphics_draw_bitmap_in_rect
• https://developer.rebble.io/docs/c/Graphics/Graphics_Context/