UI: Make Main UI Sections Collapsible

[Rakadeja]

Summary

The UI panel can become quite long, especially when all options are visible. To improve organization and reduce scrolling, the main sections ("Live Preview Options", "Live Tweaking", "Final Generation") should be collapsible, similar to standard Blender panels.

Current Behavior

All sections are always expanded, creating a long, monolithic panel.

Expected Behavior

Each major section can be collapsed by the user by clicking its header, saving vertical screen space.

Suspected Code Regions

This is a UI-only change in ui.py. The existing layout.box() elements already support this behavior natively. The task is to ensure the structure is correct. Each collapsible section should be its own box.

# ui.py -> class BF2M_PT_Panel -> draw()

# Each of these should be a distinct, collapsible box.
if props.is_prepared:
    # This should be the header for the first collapsible box
    box = layout.box()
    box.label(text="Live Preview Options", icon='TEXT')
    box.prop(props, "preview_all_glyphs")
    # ...

    # This should be the header for the second collapsible box
    box = layout.box()
    box.label(text="2. Live Tweaking", icon='SETTINGS')
    # ...

    # Rinse, repeat for other sections.