### Background
After #9344, the Ghostty theme won't change after switching systems', and reverting #9344 will bring back the issue it fixed.
The reason these two issues are related is because the scheme change is based on changes of `effectiveAppearance`, which is also affected by setting the window's `appearance` or changing `NSAppearance.currentDrawing()`.
### Changes
Instead of observing `effectiveAppearance`, we now explicitly update the color scheme of surfaces, so that we can control when it happens to avoid callback loops and redundant updates.
### Regression Tests
- [x] #8282
- [x] Reloading with `window-theme = light` should update Ghostty with the default dark theme with a dark window theme (break before [#83104ff](83104ff27a))
- [x] `window-theme = light \n macos-titlebar-style = native` should update Ghostty with the default dark theme with a light window theme
- [x] Reloading from the default config to `theme=light:3024 Day,dark:3024 Night \n window-theme = light`, should update Ghostty with the theme `3024 Day` with a light window theme (break on [#d39cc6d](d39cc6d478))
- [x] Using `theme=light:3024 Day,dark:3024 Night`; Switching the system's appearance should change Ghostty's appearance (break on [#d39cc6d](d39cc6d478))
- [x] Reloading from `theme=light:3024 Day,dark:3024 Night` with a light window theme to the default config, should update Ghostty with the default dark theme with a dark window theme
- [x] Reloading from the default config to `theme=light:3024 Day,dark:3024 Night \n window-theme=dark`, should update Ghostty with the theme `3024 Night` with a dark window theme
- [x] Reloading from `theme=light:3024 Day,dark:3024 Night \n window-theme=dark` to `theme=light:3024 Day,dark:3024 Night` with light system appearance, should update Ghostty from dark to light
- [x] Reload with quick terminal open
# Conflicts:
# macos/Sources/Features/Terminal/BaseTerminalController.swift
Fixes#2660
Rather than calculate our window frame size based on various chrome
calculations, we now utilize SwiftUI layouts and view intrinsic content
sizes with `setContentSize` to setup our content size ignoring all our
other widgets.
I'm sure there's some edge cases I'm missing here but this should be a
whole lot more reliable on the whole.
Fixes#9132
We were processing our window size defaults separate from our window
position and the result was that you'd get some incorrect behavior.
Unify the logic more to fix the positioning.
Note there is room to improve this further, I think that all initial
positioning could go into the controller completely. But I wanted to
minimize the diff for a backport.
### This PR depends on #9162#1691 doesn't seem to be an issue anymore, but changing appearance while
Ghosty is active will result in similar nastiness.
https://github.com/user-attachments/assets/fcd7761e-a521-4382-8d7a-9d93dc0806bc
### Changes
- [Sequoia/Ventura] Fix flickering new tab icon, and it also didn't
respond to window's key status change correctly
- [Sequoia/Ventura] Fix after changing appearance, tab bar may disappear
or have inconsistent background colour
- Fix initial tint of reset zoom button on Sequoia/Ventura with
`macos-titlebar-style=tabs` and all `native/transparent` titlebars
- Fix title alignment with custom font with `native/transparent`
titlebar
