Restructured project

- backend moved to backend directory
- added and initialized frontend with vue
- moved infrastructure files to infra directory

backend/src/integrations/ocr/ocr.go

@@ -0,0 +1,9 @@
+package ocr
+
+import "context"
+
+// OCR — контракт для любого OCR сервиса
+type OCR interface {
+	Recognize(ctx context.Context, image []byte) (string, error)
+	Close() error
+}