Ticket #83 PR #35 Review: pass_audit approved Phase 3: Kanban Board - Navigation, Cards, and Drag-Drop Enhancement. New Stimulus Controllers: 1. column_nav_controller.js (89 lines) - Jump-to-column, collapse/expand, progress bar 2. kanban_filter_controller.js (181 lines) - Persistent filters via localStorage, focus mode, active filter tags 3. undo_toast_controller.js (127 lines) - Undo toast after drag-drop, 5-second window Enhanced kanban_controller.js: - Event delegation for dynamic cards - Enhanced visual feedback (opacity, scale, shadow, green ring) - Keyboard support (Escape to cancel drag) - Return to original position on failed transitions Helper Methods (application_helper.rb): - column_status_styles() - Status-specific color schemes - status_icon() - SVG icons for each status - ticket_aging_status() - New/Xh/Xd badge - priority_border_color() - Color-coded borders (critical=red, high=orange, medium=yellow) - ticket_type_badge_class() - Type-specific colors (epic=purple, story=blue, bug=red) - agent_avatar_color() - Consistent color from name hash Enhanced Kanban Card features: - Ticket ID, priority dot, aging badge - Epic progress bar (completed/total subtasks) - Ticket type badge, subtasks count, comments count, blocked badge - Assignee avatar with consistent color - Rework count indicator Acceptance criteria all met: - ✓ Column counts and controls added - ✓ Cards redesigned with rich info - ✓ Drag-drop has visual feedback and undo - ✓ Filtering is persistent with saved views - ✓ Epic column enhanced with progress visualization