Restructured project

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

backend/migrations/000005_create_receipts.up.sql

@@ -0,0 +1,35 @@
+CREATE TABLE receipts
+(
+    id              BIGSERIAL PRIMARY KEY,
+    receipt_number  TEXT      NOT NULL UNIQUE,
+    ui              TEXT      NOT NULL,
+    status          INTEGER   NOT NULL,
+    issued_at       TIMESTAMP NOT NULL,
+    total_amount    REAL      NOT NULL,
+    payment_amount  REAL      NOT NULL,
+    cash_amount     REAL      NOT NULL,
+    another_amount  REAL      NOT NULL,
+    clearing_amount REAL      NOT NULL,
+    margin          REAL      NOT NULL,
+    currency        TEXT      NOT NULL,
+    payment_type    INTEGER   NOT NULL,
+    cashbox_number  INTEGER   NOT NULL,
+    cashier         TEXT,
+    name_spd        TEXT,
+    name_to         TEXT,
+    name_np         TEXT,
+    type_np         TEXT,
+    street_to       TEXT,
+    house_to        TEXT,
+    kod_soato       TEXT,
+    oblast_soato    TEXT,
+    rayon_soato     TEXT,
+    selsovet_soato  TEXT,
+    doc_num         TEXT,
+    skno_number     TEXT,
+    unp             TEXT,
+    success         TEXT,
+    created_at      TIMESTAMP DEFAULT NOW()
+);
+
+CREATE INDEX idx_receipts_issued_at ON receipts(issued_at);