Improved field value replacement and element matching

Improvements

• Improved how the I.fill command replaces values in input fields that already contain text. This resolves an edge case on some websites where clearing a field would trigger the original value to be restored, causing the new value to be appended instead of fully replacing the existing value. To ensure the value is always replaced, I.fill will now send Ctrl/Cmd + A when a field contains existing text before entering the new value.
• Improved element targeting by rebalancing attribute weights to prioritize attributes with higher intentionality, resulting in more accurate element matching.