feat: Complete UI redesign for Model Forms and Policy pages

Major UI Enhancement with shadcn/ui Components:

New Components Created:
- Input: Text input with proper styling and accessibility
- Label: Form labels using Radix UI
- Textarea: Multi-line text input
- Select: Dropdown selection with Radix UI
- Dialog: Modal dialogs for forms
- Switch: Toggle component for boolean fields

Page Redesigns:
1. ModelForm (Register New Model):
   - Professional card layout with hero section
   - Rich form labels with icons and helper text
   - Form validation and loading states
   - Improved UX with contextual information banner

2. PolicyList (Governance Policies):
   - Stats cards showing policy metrics
   - Modern table with color-coded badges
   - Feature-rich create policy dialog
   - Empty state with helpful messaging

3. PolicyViolations:
   - Alert banner summarizing violations
   - Professional table with clickable model links
   - Visual severity indicators
   - Encouraging empty state for compliance

4. ModelDetail:
   - Version stats cards
   - Clean version history table
   - Streamlined add version dialog
   - Empty state encouraging version tracking

Design Improvements:
- Consistent visual hierarchy across all pages
- Lucide icons for better visual communication
- Proper spacing and padding (follows 8px grid)
- Color-coded badges for status/scope
- Loading states and form validation
- Responsive layouts
- Professional empty states

Technical:
- Installed @radix-ui dependencies (label, select, dialog, switch)
- All components follow shadcn/ui patterns
- Maintains accessibility standards
- CSS bundle: 28.19KB (optimized for production)

Author: TamTunnel

AIGovHub/frontend/package-lock.json

@@ -15,7 +15,10 @@
     "@mantine/hooks": "^8.3.10",
     "@radix-ui/react-dialog": "^1.1.15",
     "@radix-ui/react-dropdown-menu": "^2.1.16",
+    "@radix-ui/react-label": "^2.1.8",
+    "@radix-ui/react-select": "^2.2.6",
     "@radix-ui/react-slot": "^1.2.4",
+    "@radix-ui/react-switch": "^1.2.6",
     "@radix-ui/react-tabs": "^1.1.13",
     "axios": "^1.13.2",
     "class-variance-authority": "^0.7.1",