Only some parts of Tiled properly respond to changing windows with a different Display Scale setting

@Aayushmaan-24 is already working on this.

Since Mar 10, 2026.

### Describe the bug

This might be related to #2835 (or maybe is the same thing? It seems a bit different from an outside view, but unsure if that's actually the case).

When moving Tiled between a primary monitor with 150% display scale and a secondary monitor with 100% display scale, the fonts and padding seem to resize appropriately, but the UI size/padding/etc. doesn't reflect the changes.

Example image of:
* Maximized notepad window on the primary monitor in the background, as a baseline size reference
* A smaller notepad window also on the primary monitor, for size/behavior reference of another program's behavior
* Tiled on the primary monitor


Followup example:
* Maximized notepad window still on primary monitor
* Smaller notepad window moved to secondary monitor
* Tiled moved to secondary monitor


You'll notice that Notepad feels the same size (relatively speaking) in isolation, but the window size is actually much smaller compared to when it was on the primary monitor.

Meanwhile with Tiled, the fonts are smaller, but almost everything else is basically the same size. This makes the window itself feel much larger despite technically being the same size, and also makes it seem like most UI elements have an unusually large amount of inner padding.

---

I'm not sure if this is actually Tiled or Qt. I tested with the Windows 64bit Qt6 build, but an interesting thing to note is that the Windows 32bit Qt5 build has a similar problem with slight differences: the outer window size *was* correctly adjusted, and some other things seem closer to what I would expecte too. However, some parts appear to be worse since they didn't account for the window size changing, like the sidebars.

Primary monitor example (conditions matching the first example from before):

Secondary monitor example (conditions matching the second example from before):

### Steps to reproduce

Move Tiled from one monitor to the other.

At least on my computer, you can see the adjustments take place when it gets a little over halfway across the monitor boundary.

### Expected behavior

Every aspect of Tiled to feel appropriately rescaled on the new monitor, not just some parts.

### OS version

Windows 11, 64-bit

### Tiled version

CI build from 2/20/2026 (second from last commit in #4308, commit e794b0a, from action run 22233411625)