macos: set initial terminal dimensions

macos/Sources/Features/SlideTerminal/SlideTerminalController.swift

@@ -36,6 +36,9 @@ class SlideTerminalController: BaseTerminalController {
         // make this restorable, but it isn't currently implemented.
         window.isRestorable = false
 
+        // Setup our initial size based on our configured position
+        position.setLoaded(window)
+
         // Setup our content
         window.contentView = NSHostingView(rootView: TerminalView(
             ghostty: self.ghostty,

macos/Sources/Features/SlideTerminal/SlideTerminalPosition.swift

@@ -3,6 +3,20 @@ import Cocoa
 enum SlideTerminalPosition {
     case top
 
+    /// Set the loaded state for a window.
+    func setLoaded(_ window: NSWindow) {
+        guard let screen = window.screen ?? NSScreen.main else { return }
+        switch (self) {
+        case .top:
+            window.setFrame(.init(
+                origin: window.frame.origin,
+                size: .init(
+                    width: screen.frame.width,
+                    height: screen.frame.height / 4)
+            ), display: false)
+        }
+    }
+
     /// Set the initial state for a window for animating out of this position.
     func setInitial(in window: NSWindow, on screen: NSScreen) {
         // We always start invisible

macos/Sources/Features/SlideTerminal/SlideTerminalWindow.swift

@@ -23,6 +23,9 @@ class SlideTerminalWindow: NSWindow {
         // and lets us render off screen.
         self.level = .popUpMenu
 
+        // This plus the level above was what was needed for the animation to work,
+        // because it gets the window off screen properly. Plus we add some fields
+        // we just want the behavior of.
         self.collectionBehavior = [
             // We want this to be part of every space because it is a singleton.
             .canJoinAllSpaces,