[Phase 2] Implement receipt management endpoints (5 missing)

[creatiVision]

Missing receipt endpoints:

• receipts/add — Add receipt without file
• receipts/delete/id_by_customer — Delete receipt
• receipts/restore/id_by_customer — Restore deleted receipt
• receipts/addBatch — Batch add receipts
• receipts/assigned-transactions/get — Get transactions for receipt