feat: add download CLI commands with ref support (#183)

* feat: add download and waitfordownload CLI commands

Add CLI support for the existing download functionality in the daemon:

- `download <selector> <path>`: Click an element to trigger download
  and save to specified path
- `wait --download [path] [--timeout ms]`: Wait for any download to
  complete, optionally save to path with configurable timeout

Includes comprehensive unit tests and help documentation.

* fix: download command ref support and output message

- Fix handleDownload to use browser.getLocator() for ref selector support
- Fix CLI output to show "Downloaded to" instead of "Screenshot saved"

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

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Chris Tate <chris@ctate.dev>

src/actions.ts

@@ -1074,11 +1074,9 @@ async function handleDownload(
   browser: BrowserManager
 ): Promise<Response> {
   const page = browser.getPage();
+  const locator = browser.getLocator(command.selector);
 
-  const [download] = await Promise.all([
-    page.waitForEvent('download'),
-    page.click(command.selector),
-  ]);
+  const [download] = await Promise.all([page.waitForEvent('download'), locator.click()]);
 
   await download.saveAs(command.path);
   return successResponse(command.id, {