feat(sqlite): add SQLite type mapping and conversion functions

* Implement SQLiteToCanonicalTypes for type mapping
* Add ConvertSQLiteToCanonical and ConvertCanonicalToSQLite functions
* Update mapDataType to utilize new conversion logic

pkg/readers/pgsql/queries.go

@@ -270,7 +270,15 @@ func (r *Reader) queryColumns(schemaName string) (map[string]map[string]*models.
 		}
 
 		if numPrecision != nil {
-			column.Precision = *numPrecision
+			// For integer and serial types, numeric_precision is a bit-width (32, 64, 16)
+			// not a user-visible column parameter. Only store precision for types where
+			// it represents actual decimal/scale precision (numeric, decimal, float).
+			switch column.Type {
+			case "integer", "bigint", "smallint", "serial", "bigserial", "smallserial":
+				// skip — bit-width, not a column parameter
+			default:
+				column.Precision = *numPrecision
+			}
 		}
 
 		if numScale != nil {