fix(cli): add detached: !isWindows() to dashboard spawn for correct process cleanup

Without detached:true on Unix, killProcessTree(pid) calls process.kill(-pid)
which targets a process group the child never owns — ESRCH causes fallback to
direct kill, leaving grandchild processes alive. Matches the pattern already
used in start.ts lines 782 and 795.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/cli/src/commands/dashboard.ts

@@ -2,7 +2,7 @@ import { spawn } from "node:child_process";
 import { resolve } from "node:path";
 import chalk from "chalk";
 import type { Command } from "commander";
-import { killProcessTree, loadConfig } from "@composio/ao-core";
+import { isWindows, killProcessTree, loadConfig } from "@composio/ao-core";
 import { findWebDir, buildDashboardEnv, waitForPortAndOpen } from "../lib/web-dir.js";
 import {
   findRunningDashboardPid,
@@ -67,6 +67,7 @@ export function registerDashboard(program: Command): void {
       const child = spawn("node", [startScript], {
         cwd: webDir,
         stdio: ["inherit", "inherit", "pipe"],
+        detached: !isWindows(),
         env,
       });