feat(digital-signatures): simplify form, add TIFF support, subcategories, download options

- Remove 'initials' type, expirationDate, legalStatus, usageNotes fields
- Add subcategory field with creatable input + 6 default categories
- Add TIFF upload support with client-side utif2 decode for preview
- Store original TIFF data separately for faithful downloads
- Add download dropdown: Original file, Word (.docx), PDF (.pdf)
- Group assets by subcategory in list view
- Add subcategory filter in search bar
- Install docx, jspdf, utif2 packages
- Closes 3.07

package.json

@@ -9,11 +9,13 @@
     "lint": "eslint"
   },
   "dependencies": {
+    "@prisma/client": "^6.19.2",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
+    "docx": "^9.6.0",
+    "jspdf": "^4.2.0",
     "jszip": "^3.10.1",
     "lucide-react": "^0.564.0",
-    "@prisma/client": "^6.19.2",
     "minio": "^8.0.6",
     "next": "16.1.6",
     "next-auth": "^4.24.13",
@@ -23,6 +25,7 @@
     "react-dom": "19.2.3",
     "tailwind-merge": "^3.4.1",
     "tesseract.js": "^7.0.0",
+    "utif2": "^4.1.0",
     "uuid": "^13.0.0"
   },
   "devDependencies": {