feat: add Ctrl+X cut shortcut for timeline elements (#672)

Adds a "cut-selected" action that copies selected elements to
clipboard and then deletes them, enabling standard cut behavior.

Note: Drag/drop elements to other tracks was already implemented.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/web/src/hooks/actions/use-editor-actions.ts

@@ -274,6 +274,33 @@ export function useEditorActions() {
 		undefined,
 	);
 
+	useActionHandler(
+		"cut-selected",
+		() => {
+			if (selectedElements.length === 0) return;
+
+			// Copy elements to clipboard
+			const results = editor.timeline.getElementsWithTracks({
+				elements: selectedElements,
+			});
+			const items = results.map(({ track, element }) => {
+				const { ...elementWithoutId } = element;
+				return {
+					trackId: track.id,
+					trackType: track.type,
+					element: elementWithoutId,
+				};
+			});
+			setClipboard({ items });
+
+			// Delete the selected elements
+			editor.timeline.deleteElements({
+				elements: selectedElements,
+			});
+		},
+		undefined,
+	);
+
 	useActionHandler(
 		"paste-copied",
 		() => {

apps/web/src/lib/actions/definitions.ts

@@ -95,6 +95,11 @@ export const ACTIONS = {
 		category: "editing",
 		defaultShortcuts: ["ctrl+c"],
 	},
+	"cut-selected": {
+		description: "Cut selected elements",
+		category: "editing",
+		defaultShortcuts: ["ctrl+x"],
+	},
 	"paste-copied": {
 		description: "Paste elements at playhead",
 		category: "editing",