macos: add AppleScript commands for text input, key, and mouse events

Add five new AppleScript commands to Ghostty.sdef mirroring the existing
App Intents for terminal input:

- `input text`: send text to a terminal as if pasted
- `send key`: simulate a keyboard event with optional action and modifiers
- `send mouse button`: send a mouse button press/release event
- `send mouse position`: send a mouse cursor position event
- `send mouse scroll`: send a scroll event with precision and momentum

A shared `input action` enumeration (press/release) is used by both key
and mouse button commands. Modifier keys are passed as a comma-separated
string parameter (shift, control, option, command).

macos/Sources/Features/AppleScript/ScriptMouseScrollCommand.swift

@@ -0,0 +1,69 @@
+import AppKit
+
+/// Handler for the `send mouse scroll` AppleScript command defined in `Ghostty.sdef`.
+///
+/// Cocoa scripting instantiates this class because the command's `<cocoa>` element
+/// specifies `class="GhosttyScriptMouseScrollCommand"`. The runtime calls
+/// `performDefaultImplementation()` to execute the command.
+@MainActor
+@objc(GhosttyScriptMouseScrollCommand)
+final class ScriptMouseScrollCommand: NSScriptCommand {
+    override func performDefaultImplementation() -> Any? {
+        guard let x = evaluatedArguments?["x"] as? Double else {
+            scriptErrorNumber = errAEParamMissed
+            scriptErrorString = "Missing x scroll delta."
+            return nil
+        }
+
+        guard let y = evaluatedArguments?["y"] as? Double else {
+            scriptErrorNumber = errAEParamMissed
+            scriptErrorString = "Missing y scroll delta."
+            return nil
+        }
+
+        guard let terminal = evaluatedArguments?["terminal"] as? ScriptTerminal else {
+            scriptErrorNumber = errAEParamMissed
+            scriptErrorString = "Missing terminal target."
+            return nil
+        }
+
+        guard let surfaceView = terminal.surfaceView else {
+            scriptErrorNumber = errAEEventFailed
+            scriptErrorString = "Terminal surface is no longer available."
+            return nil
+        }
+
+        guard let surface = surfaceView.surfaceModel else {
+            scriptErrorNumber = errAEEventFailed
+            scriptErrorString = "Terminal surface model is not available."
+            return nil
+        }
+
+        let precision = evaluatedArguments?["precision"] as? Bool ?? false
+
+        let momentum: Ghostty.Input.Momentum
+        if let momentumCode = evaluatedArguments?["momentum"] as? UInt32 {
+            switch momentumCode {
+            case "SMno".fourCharCode: momentum = .none
+            case "SMbg".fourCharCode: momentum = .began
+            case "SMch".fourCharCode: momentum = .changed
+            case "SMen".fourCharCode: momentum = .ended
+            case "SMcn".fourCharCode: momentum = .cancelled
+            case "SMmb".fourCharCode: momentum = .mayBegin
+            case "SMst".fourCharCode: momentum = .stationary
+            default: momentum = .none
+            }
+        } else {
+            momentum = .none
+        }
+
+        let scrollEvent = Ghostty.Input.MouseScrollEvent(
+            x: x,
+            y: y,
+            mods: .init(precision: precision, momentum: momentum)
+        )
+        surface.sendMouseScroll(scrollEvent)
+
+        return nil
+    }
+}