Add web UX with dashboard, import wizard, backup management

- SPA frontend (static/index.html): 4-step wizard flow
  (Upload → Review → Import → Report) + Dashboard bar + Backup UI
- FastAPI server (server.py) with 14 API endpoints
- New endpoints: /api/status, /api/backups, /api/backup/restore
- Updated README with web UX usage
- Added web deps: fastapi, uvicorn, python-multipart

README.md

@@ -38,6 +38,42 @@ pip install -r requirements.txt
 python main.py seed-data/import_seed.csv --db /path/to/assets.db [--dry-run]
 ```
 
+## Web UX
+
+Standalone web interface for uploading, previewing, and importing Cantaloupe data:
+
+```bash
+cd ~/projects/canteen-seed-import
+source .venv/bin/activate
+pip install -r requirements.txt  # ensure web deps are installed
+
+python -m web_ux.main --port 8089
+```
+
+Then open **http://localhost:8089**
+
+Features:
+- 📊 **Dashboard** — DB stats, class/make breakdown, GPS coverage
+- 📤 **Import** — Drag-and-drop Excel upload, preview parsed data, choose seed/update mode, run import with automatic backup
+- 💾 **Backup** — Create/manage/compare/restore GPS+photo backups
+- 📋 **Report** — View the latest validation report
+- ⚙️ **Config** — View header mappings and handbook reference
+
+### API Endpoints
+
+| Method | Path | Description |
+|--------|------|-------------|
+| GET | /api/status | DB stats and health |
+| GET | /api/config | Header mappings + handbook info |
+| POST | /api/upload | Upload Excel file, returns preview token |
+| GET | /api/preview/{token} | Get paginated preview data |
+| POST | /api/import | Run import (seed/update) |
+| GET | /api/report | Latest validation report |
+| POST | /api/backup | Create database backup |
+| GET | /api/backups | List existing backups |
+| POST | /api/backup/compare | Compare backup to current DB |
+| POST | /api/backup/restore | Restore preserved fields from backup |
+
 ## Integration
 
 Once validated, this tool will be integrated into the [Canteen Admin Server](https://admin.canteen.ourpad.casa).