fix: set valor=0 in detallePedido; parse full factura (prefix+number) in search

- json_generator: send valor:0 per item instead of PRECIO from Firebird
- test_rda + transaccion: accept "LHXC03726" format — extracts numeric part
  for NUM_FACTURA and letter prefix for PREFIJO filter when prefix present

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/services/json_generator.py

@@ -153,7 +153,7 @@ def generar_rda_paciente(rows: list, default_profesional: str = "", default_espe
             "codigoBodega": "00",
             "cantidad": 1,
             "tipoUnidad": "D",
-            "valor": float(row.get("PRECIO") or 0),
+            "valor": 0,
             "descuento": float(row.get("DESCUENTO") or 0),
             "porcentajeIva": 0,
             "impConsumo": 0,