Align visual design of Lora Randomizer widget with Loras widget for
consistent UI/UX across the node interface.
Changes:
- Unified border-radius system (4px→6px for containers, 6px for inputs)
- Standardized padding (12px→6px for widget container)
- Reduced slider height (32px→24px) following desktop tool best practices
- Aligned font sizes (12px→13px for labels, 11px→12px for buttons)
- Unified spacing system (16px→6px for sections, 8px→6px for gaps)
- Adjusted widget minimum height (510px→448px) to reflect layout changes