macos: setup colorspace in base terminal controller

Fixes #2519

This sets up the colorspace for terminal windows in the base controller.

This also modifies some of our logic so its easier for subclasses of
base controllers to specify custom logic when the configuration reloads,
since that's likely to be a common thing.

macos/Sources/Features/QuickTerminal/QuickTerminalController.swift

@@ -33,11 +33,6 @@ class QuickTerminalController: BaseTerminalController {
             selector: #selector(onToggleFullscreen),
             name: Ghostty.Notification.ghosttyToggleFullscreen,
             object: nil)
-        center.addObserver(
-            self,
-            selector: #selector(ghosttyDidReloadConfig),
-            name: Ghostty.Notification.ghosttyDidReloadConfig,
-            object: nil)
     }
 
     required init?(coder: NSCoder) {
@@ -53,6 +48,8 @@ class QuickTerminalController: BaseTerminalController {
     // MARK: NSWindowController
 
     override func windowDidLoad() {
+        super.windowDidLoad()
+
         guard let window = self.window else { return }
 
         // The controller is the window delegate so we can detect events such as
@@ -63,9 +60,6 @@ class QuickTerminalController: BaseTerminalController {
         // make this restorable, but it isn't currently implemented.
         window.isRestorable = false
 
-        // Setup our configured appearance that we support.
-        syncAppearance()
-
         // Setup our initial size based on our configured position
         position.setLoaded(window)
 
@@ -297,35 +291,6 @@ class QuickTerminalController: BaseTerminalController {
         })
     }
 
-    private func syncAppearance() {
-        guard let window else { return }
-
-        // If our window is not visible, then delay this. This is possible specifically
-        // during state restoration but probably in other scenarios as well. To delay,
-        // we just loop directly on the dispatch queue. We have to delay because some
-        // APIs such as window blur have no effect unless the window is visible.
-        guard window.isVisible else {
-            // Weak window so that if the window changes or is destroyed we aren't holding a ref
-            DispatchQueue.main.async { [weak self] in self?.syncAppearance() }
-            return
-        }
-
-        // If we have window transparency then set it transparent. Otherwise set it opaque.
-        if (ghostty.config.backgroundOpacity < 1) {
-            window.isOpaque = false
-
-            // This is weird, but we don't use ".clear" because this creates a look that
-            // matches Terminal.app much more closer. This lets users transition from
-            // Terminal.app more easily.
-            window.backgroundColor = .white.withAlphaComponent(0.001)
-
-            ghostty_set_window_background_blur(ghostty.app, Unmanaged.passUnretained(window).toOpaque())
-        } else {
-            window.isOpaque = true
-            window.backgroundColor = .windowBackgroundColor
-        }
-    }
-
     // MARK: First Responder
 
     @IBAction override func closeWindow(_ sender: Any) {
@@ -357,10 +322,6 @@ class QuickTerminalController: BaseTerminalController {
         // We ignore the requested mode and always use non-native for the quick terminal
         toggleFullscreen(mode: .nonNative)
     }
-
-    @objc private func ghosttyDidReloadConfig(notification: SwiftUI.Notification) {
-        syncAppearance()
-    }
 }
 
 extension Notification.Name {