feat: add undo action and fix hotkeys rendering (#438)

* Fix prompt action undo and hotkeys rendering

* Fix prompt action test typechecks

* Simplify undo and hotkeys PR

* Fix editor formatting

packages/coding-agent/src/modes/controllers/input-controller.ts

@@ -535,6 +535,7 @@ export class InputController {
 			keybindings: this.ctx.keybindings,
 			copyCurrentLine: () => this.handleCopyCurrentLine(),
 			copyPrompt: () => this.handleCopyPrompt(),
+			undo: prefix => this.ctx.editor.undoPastTransientText(prefix),
 			moveCursorToMessageEnd: () => this.ctx.editor.moveToMessageEnd(),
 			moveCursorToMessageStart: () => this.ctx.editor.moveToMessageStart(),
 			moveCursorToLineStart: () => this.ctx.editor.moveToLineStart(),