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/routes/transaccion.py

@@ -26,9 +26,12 @@ def _query_rows(cfg, query_text, factura, fecha_inicio, fecha_fin):
         return None, msg, None
     nums = _re.findall(r'\d+', factura or "")
     num_val = int(nums[-1]) if nums else (factura or "")
+    prefix = _re.sub(r'[\d\s]', '', factura or "").strip().upper()
     params = {"fecha_ini": f"{fecha_inicio} 00:00:00", "fecha_fin": f"{fecha_fin} 23:59:59"}
     if ":num_factura" in query_text:
         params["num_factura"] = num_val
+    if ":prefijo" in query_text:
+        params["prefijo"] = prefix
     ok2, err, rows = fb.execute_query(query_text, params)
     fb.disconnect()
     if not ok2: