Workflow Builder: Drag & Drop

Improved the visual design and interactions for building workflows by using drag-and-drop reordering.

• Full drag-and-drop reordering — Complete system for reordering workflow nodes with zone detection and UX improvements
• Visual polish — Node styling, branch path alignment, white borders, arrow gaps
• Condition builder — Category list and breadcrumb pattern for building conditions
• Canvas improvements — Centering fix for sidebar, minimap/node spacing
• Edit mode — Floating header bar with auto-save drafts