Tiled windows grow beyond tile bounds when app changes its own size

**Describe the bug**
When a tiled window internally changes its own height — for example, toggling "Show Menubar" in GNOME Terminal or opening a new tab that introduces a tab bar — the window grows taller than its assigned tile, overflowing into adjacent tile space. TilingShell does not re-enforce the tile boundary after this kind of app-driven resize.

**To Reproduce**
Steps to reproduce the behavior:
1. Tile a GNOME Terminal window into a tile (e.g. the top half of the screen)
2. Inside the terminal, enable the menubar via View → Show Menubar, or open a new tab for the first time (which adds a tab bar)
3. The window height increases beyond the tile boundary

**Screenshots**

https://github.com/user-attachments/assets/a25c05c7-9969-47c1-98ae-8504a4cddd05

**Information (please complete the following):**
- Tiling Shell version: v17.3 (71)
- GNOME version: 49.4

**Additional context**
This happens when an application emits an internal geometry/size-hint change rather than the user manually resizing the window. TilingShell does not intercept and clamp the new size back to the tile boundary in this case. Other apps or UI events that change a window's preferred height from within (adding toolbars, tab bars, etc.) likely trigger the same issue.