Kanban board, Project Management, Proposals/Quotes, Time Tracking, Custom Fields

- Kanban board with drag-and-drop per stage, colour-coded cards, score bars
- Project Management with milestones, Gantt timeline, inline add milestone/task
- Proposal/Quote builder with line items, VAT, terms, e-signature capture
- Time Tracking with stopwatch, manual entry, hours-by-project chart
- Custom Fields system: admin-defined fields per entity (leads/customers/
  projects/opportunities) with drag-and-drop reordering in settings
- Reusable CustomFieldsSection component for entity detail pages
- Customers API endpoint
- All builds pass with zero errors

package.json

@@ -24,6 +24,9 @@
     "lint": "eslint"
   },
   "dependencies": {
+    "@dnd-kit/core": "^6.3.1",
+    "@dnd-kit/sortable": "^10.0.0",
+    "@dnd-kit/utilities": "^3.2.2",
     "@emoji-mart/data": "^1.2.1",
     "@emoji-mart/react": "^1.1.1",
     "@hookform/resolvers": "^3.9.1",