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-lock.json

@@ -8,6 +8,9 @@
       "name": "frontend",
       "version": "0.1.0",
       "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",
@@ -229,6 +232,59 @@
         "kuler": "^2.0.0"
       }
     },
+    "node_modules/@dnd-kit/accessibility": {
+      "version": "3.1.1",
+      "resolved": "https://registry.npmjs.org/@dnd-kit/accessibility/-/accessibility-3.1.1.tgz",
+      "integrity": "sha512-2P+YgaXF+gRsIihwwY1gCsQSYnu9Zyj2py8kY5fFvUM1qm2WA2u639R6YNVfU4GWr+ZM5mqEsfHZZLoRONbemw==",
+      "license": "MIT",
+      "dependencies": {
+        "tslib": "^2.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=16.8.0"
+      }
+    },
+    "node_modules/@dnd-kit/core": {
+      "version": "6.3.1",
+      "resolved": "https://registry.npmjs.org/@dnd-kit/core/-/core-6.3.1.tgz",
+      "integrity": "sha512-xkGBRQQab4RLwgXxoqETICr6S5JlogafbhNsidmrkVv2YRs5MLwpjoF2qpiGjQt8S9AoxtIV603s0GIUpY5eYQ==",
+      "license": "MIT",
+      "dependencies": {
+        "@dnd-kit/accessibility": "^3.1.1",
+        "@dnd-kit/utilities": "^3.2.2",
+        "tslib": "^2.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=16.8.0",
+        "react-dom": ">=16.8.0"
+      }
+    },
+    "node_modules/@dnd-kit/sortable": {
+      "version": "10.0.0",
+      "resolved": "https://registry.npmjs.org/@dnd-kit/sortable/-/sortable-10.0.0.tgz",
+      "integrity": "sha512-+xqhmIIzvAYMGfBYYnbKuNicfSsk4RksY2XdmJhT+HAC01nix6fHCztU68jooFiMUB01Ky3F0FyOvhG/BZrWkg==",
+      "license": "MIT",
+      "dependencies": {
+        "@dnd-kit/utilities": "^3.2.2",
+        "tslib": "^2.0.0"
+      },
+      "peerDependencies": {
+        "@dnd-kit/core": "^6.3.0",
+        "react": ">=16.8.0"
+      }
+    },
+    "node_modules/@dnd-kit/utilities": {
+      "version": "3.2.2",
+      "resolved": "https://registry.npmjs.org/@dnd-kit/utilities/-/utilities-3.2.2.tgz",
+      "integrity": "sha512-+MKAJEOfaBe5SmV6t34p80MMKhjvUz0vRrvVJbPT0WElzaOJ/1xs+D+KDv+tD/NE5ujfrChEcshd4fLn0wpiqg==",
+      "license": "MIT",
+      "dependencies": {
+        "tslib": "^2.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=16.8.0"
+      }
+    },
     "node_modules/@emnapi/core": {
       "version": "1.10.0",
       "resolved": "https://registry.npmjs.org/@emnapi/core/-/core-1.10.0.tgz",