Add mod categories and fix submenu hover bug

[atheran2]

Summary

• Mod Categories: Added a category system for organizing mods

  • Right-click context menu to assign mods to categories or create new ones
  • "Manage Categories" dialog accessible from the View menu
  • Support for global categories (shared across profiles) and profile-specific overrides
  • Visual grouping in the mod list by category (toggle via View > Group by Category)
  • Drag-and-drop support to move mods between categories

• Submenu Bug Fix: Fixed an issue where submenus would disappear when moving the cursor from the parent menu item to the submenu, making it impossible to select options like themes, profiles, or presets. Added transparent hit-test area to bridge the gap between menu and submenu.

Test Plan

• Right-click a mod and verify category selection dialog appears
• Create a new category and assign a mod to it
• Enable "Group by Category" from View menu and verify mods are grouped
• Open "Manage Categories" dialog and verify categories can be added/edited/deleted
• Create a profile-specific category and verify it only appears in that profile
• Switch profiles and verify category assignments are per-profile
• Hover over menu items with submenus (Theme, Profiles, Presets) and verify submenus remain open when moving cursor to them
• Verify theme/profile/preset selection works correctly