feat: initial project setup

- Add .NET 8 backend with Clean Architecture
- Add React + Vite + TypeScript frontend
- Implement authentication with JWT
- Implement Azure Blob Storage client
- Implement OCR integration
- Implement supplier matching service
- Implement voucher generation
- Implement Fortnox provider
- Add unit and integration tests
- Add Docker Compose configuration

backend/global.json

@@ -0,0 +1,6 @@
+{
+  "sdk": {
+    "version": "8.0.100",
+    "rollForward": "latestFeature"
+  }
+}