✨ Pinch to increase/decrease font size

### Description

We can do pinch-to-zoom, but it has to be smooth.

Perhaps we pinch and initially zoom during the gesture (not change the font size), then after the gesture ends, reset the zoom and adjust the font size to the same visual size when it was previously zoomed which would wrap the text as expected.

That would appear to the user like this:
1. Gesture (Pinch to zoom) starts
2. Gesture ends
3. Text immediately reflows to wrap

What actually happens:
1. Gesture (pinch-to-zoom) starts
2. Text view zoomed - remaining anchored to the left
3. Gesture ends
4. Zoom amount multiplier captured
5. Text view zoom restored
6. Font size is multiplied by the zoom amount multiplier previously captured
7. This gives the appearance of the text reflowing to wrap

This behavior can be seen when looking at the Find Navigator, doing a search, and resizing the navigator sidebar. Notice it doesn't reflow the text until releasing the mouse to commit the size.

Start by examining the Find Navigator and navigator sidebar resize behavior described in the issue, focusing on how zooming is applied during the gesture and committed afterward. Implement pinch handling so the text remains visually scaled during the gesture, then resets zoom and reflows at the corresponding font size when the gesture ends; done means the text rewraps only after release.

由索引模型根據 Issue 內容生成。