[Frontend] Generic Sortable Data Table Component

[armorbreak001]

Fixes #273

Changes

• DataTable.tsx: New generic, reusable <DataTable data={[]} columns={[]} /> component
  • Uses @tanstack/react-table v8 (headless — logic hooks only, custom rendering)
  • Column sorting: Click any header to toggle asc → desc → none; sort indicator arrow shown
  • Empty state: Sleek glassmorphism-styled "No Data Available" message when data array is empty
  • Styling: Tailwind CSS matching existing dark theme (stellar-navy, stellar-lightNavy, violet-400 accents)
  • Zebra striping: Alternating row backgrounds for readability
• package.json: Added @tanstack/react-table dependency
• index.ts: Exported DataTable from components/ui barrel file

Acceptance Criteria Met

• Scaffold a <DataTable data={[]} columns={[]} /> component
• Implement basic Ascending/Descending column sorting when clicking the column header
• Build a sleek "No Data Available" state if the data array is empty
• Integrate Tailwind styling mimicking the glassmorphism dark theme

How to Verify

1. cd frontend && npm install
2. Import: import { DataTable } from '@/components/ui'
3. Define columns with ColumnDef[] and pass data array
4. Click column headers → sort toggles asc/desc/clear
5. Pass empty data={[]} → shows styled empty state