fix(mcp): use Clack multiselect for the client picker

The #305 Clack migration removed @inquirer/prompts, but the mcp install client picker still imported checkbox from it — undeclared after the rebase and broken on a clean install. Add a multiselect wrapper to lib/prompts.ts (matching the existing confirm/text/password Clack wrappers, with the same cancel→throwUserAbort handling) and route pickClients through it. No behavior change to the picker.

Author: rafa-thayto

packages/cli-core/src/commands/mcp/shared.ts

@@ -2,7 +2,6 @@
  * Shared options and helpers for `clerk mcp` subcommands.
  */
 
-import { ttyContext } from "../../lib/listage.ts";
 import { getMcpUrl } from "../../lib/environment.ts";
 import { CliError, ERROR_CODE, errorMessage, throwUsageError } from "../../lib/errors.ts";
 import { log } from "../../lib/log.ts";
@@ -67,28 +66,16 @@ export function resolveClients(ids: readonly string[]): McpClient[] {
 export async function pickClients(detected: McpClient[]): Promise<McpClient[]> {
   if (detected.length === 0) return [];
   if (detected.length === 1) return detected;
-  // Imported lazily (like `doctor`/`update` do): a top-level import of
-  // `@inquirer/prompts` is resolved at module load, which breaks tests that
-  // mock the module with a partial shape that omits `checkbox`.
-  const { checkbox } = await import("@inquirer/prompts");
-  const tty = ttyContext();
-  try {
-    const selected = await checkbox<ClientId>(
-      {
-        message: "Select MCP clients to install into:",
-        choices: detected.map((c) => ({
-          name: `${c.displayName} (${c.scope})`,
-          value: c.id,
-          checked: true,
-        })),
-        required: true,
-      },
-      tty ? { input: tty.input } : undefined,
-    );
-    return resolveClients(selected);
-  } finally {
-    tty?.close();
-  }
+  // Imported lazily (like `doctor` does) so the prompt layer stays off the
+  // module-load path for non-interactive callers and tests.
+  const { multiselect } = await import("../../lib/prompts.ts");
+  const selected = await multiselect<ClientId>({
+    message: "Select MCP clients to install into:",
+    options: detected.map((c) => ({ value: c.id, label: `${c.displayName} (${c.scope})` })),
+    initialValues: detected.map((c) => c.id),
+    required: true,
+  });
+  return resolveClients(selected);
 }
 
 export async function targetClients(options: McpOptions, cwd: string): Promise<McpClient[]> {

packages/cli-core/src/lib/prompts.ts

@@ -9,6 +9,8 @@ import {
   isCancel,
   text as clackText,
   password as clackPassword,
+  multiselect as clackMultiselect,
+  type Option as ClackOption,
 } from "@clack/prompts";
 import { editAsync } from "external-editor";
 import { throwUserAbort } from "./errors.ts";
@@ -80,6 +82,30 @@ export async function confirm(config: { message: string; default?: boolean }): P
   }
 }
 
+/** Multi-select checklist. Returns the chosen values (at least one when required). */
+export async function multiselect<T>(config: {
+  message: string;
+  options: { value: T; label: string; hint?: string }[];
+  initialValues?: T[];
+  required?: boolean;
+}): Promise<T[]> {
+  const tty = ttyContext();
+  try {
+    const result = await clackMultiselect<T>({
+      message: config.message,
+      // `Option<T>` is a conditional type a naked generic can't satisfy
+      // structurally; our shape provides `value` + `label`, valid in both branches.
+      options: config.options as ClackOption<T>[],
+      initialValues: config.initialValues,
+      required: config.required ?? true,
+      input: tty?.input,
+    });
+    return unwrap(result);
+  } finally {
+    tty?.close();
+  }
+}
+
 /** Single-line text input. */
 export async function text(config: {
   message: string;