Add Znakopis feature with document and sentence management

- Implemented Znakopis page with document and sentence CRUD operations
- Added backend routes for documents and sentences
- Created UI components for sentence editing and display
- Added sentence store for state management
- Integrated select component for document selection
- Updated README with Phase 3 completion status
- Removed obsolete fix-colors.md file

packages/frontend/package.json

@@ -13,6 +13,7 @@
   "dependencies": {
     "@dnd-kit/core": "^6.1.0",
     "@dnd-kit/sortable": "^8.0.0",
+    "@dnd-kit/utilities": "^3.2.2",
     "@radix-ui/react-dialog": "^1.0.5",
     "@radix-ui/react-dropdown-menu": "^2.0.6",
     "@radix-ui/react-label": "^2.0.2",
@@ -27,6 +28,7 @@
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "react-router-dom": "^6.21.1",
+    "sonner": "^2.0.7",
     "tailwind-merge": "^2.2.0",
     "tailwindcss-animate": "^1.0.7",
     "zod": "^3.22.4",