fix: Resolved technical debt - updated TODO/FIXME items: fixed UPDATE query in formproduct.cpp, corrected toDouble() in itemnumberdelegate.cpp, added ElementType enumeration, implemented composition deletion in formelementlist.cpp, updated README

gui/formproduct.cpp

@@ -279,9 +279,8 @@ void formProduct::save()
             ";";
 
         ElementComp = "UPDATE ELEMENTCOMPOSITION SET "
-            "CODE = :CODE, ELEMENT_CODE = :ELEMENT_CODE, ELEMENT_AMOUNT = :ELEMENT_AMOUNT, ELEMENT_PRICE := ELEMENT_PRICE "
-            "WHERE "
-            ";";
+                      "ELEMENT_AMOUNT = :ELEMENT_AMOUNT "
+                      "WHERE CODE = :CODE AND ELEMENT_CODE = :ELEMENT_CODE";
     }
 
 
@@ -442,20 +441,30 @@ bool formProduct::InsertElement(QString ID, QModelIndex index)
         }
 
         // TODO: mirar de hacer esto con una enumeración o algo que automice el porceso:
+        // Use enumeration for element types
         switch (qry.value(qry.record().indexOf("TYPE1")).toInt())
         {
-            case 0:
+            case ElementType::Composed:
                 setLineType("CO", index);             // type
                 break;
-            case 1:
+            case ElementType::Material:
                 setLineType("MT", index);             // type
                 break;
-            case 2:
+            case ElementType::ManPower:
                 setLineType("MO", index);             // type
                 break;
-            case 3:
+            case ElementType::Machinery:
                 setLineType("MQ", index);             // type
                 break;
+            case ElementType::Subcontracted:
+                setLineType("SC", index);             // type
+                break;
+            case ElementType::Other:
+                setLineType("OT", index);             // type
+                break;
+            default:
+                setLineType("UNKNOWN", index);        // type
+                break;
         }
     }
     else