Improve text addition

[maruuk]

1. Move the color palette higher up. Placing it at the very bottom conflicts with Android gestures, especially when the navigation bar is hidden. I have to open the keyboard to change the text color; otherwise, swiping at the bottom switches to another app.
2. Add a visible text input field. Currently, you have to click somewhere, but it’s not obvious. Nothing appeared when I selected the text-adding function, so I thought the app was freezing.