Layer settings visibility checkbox desync for non-default height layers

[dzole0311]

Based on comment: #62 (comment)

Steps:

• Add a layer at a different height/level
• Open layer settings
• Observe checkbox unchecked while layer is visible
• Check the box > layer disappears
• Checkbox cannot be toggled back reliably

Expected:

• Checkbox state matches actual visibility; toggling is reversible

Actual:

• UI state and layer visibility diverge; toggle gets stuck

Hint: Probably worth checking the LayersTool + layer visibility state at per-level/per-height rendering path