Add terminal setup command for Shift+Enter and Ctrl+Enter support (#3289)

Co-authored-by: jacob314 <jacob314@gmail.com>

packages/cli/src/ui/commands/terminalSetupCommand.ts

@@ -0,0 +1,45 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { MessageActionReturn, SlashCommand, CommandKind } from './types.js';
+import { terminalSetup } from '../utils/terminalSetup.js';
+
+/**
+ * Command to configure terminal keybindings for multiline input support.
+ *
+ * This command automatically detects and configures VS Code, Cursor, and Windsurf
+ * to support Shift+Enter and Ctrl+Enter for multiline input.
+ */
+export const terminalSetupCommand: SlashCommand = {
+  name: 'terminal-setup',
+  description:
+    'Configure terminal keybindings for multiline input (VS Code, Cursor, Windsurf)',
+  kind: CommandKind.BUILT_IN,
+
+  action: async (): Promise<MessageActionReturn> => {
+    try {
+      const result = await terminalSetup();
+
+      let content = result.message;
+      if (result.requiresRestart) {
+        content +=
+          '\n\nPlease restart your terminal for the changes to take effect.';
+      }
+
+      return {
+        type: 'message',
+        content,
+        messageType: result.success ? 'info' : 'error',
+      };
+    } catch (error) {
+      return {
+        type: 'message',
+        content: `Failed to configure terminal: ${error}`,
+        messageType: 'error',
+      };
+    }
+  },
+};