v1.2.0 - Sidebar UI redesign

Changes

• Redesigned main window: replaced the single cramped toolbar row with a collapsible sidebar, grouped into File, Edit mode, Grid & table, Export settings, and View sections
• Sidebar scrolls if expanded sections exceed the window height
• Default export format changed to WebP

Previous release (v1.1.0)

• Drag-and-drop (single image to open, multiple to batch-convert)
• "Convert files…" multi-file batch conversion with auto-save
• Chroma key (color-to-transparent) tool
• More resilient error handling (a failed tile/file no longer aborts the whole batch)