fix(cli): open Chromium webview logins visibly

[suatsulun]

Summary

• launch interactive cookie-login flows in a visible Chromium-family browser
• detect Chrome, Chromium, Brave, Edge, Opera GX, Opera, and Vivaldi, with an explicit browser-path override
• use an isolated temporary profile and a nonzero DevTools port so Chromium does not advertise WebDriver automation
• clean up the browser process and temporary profile after login

Verification

• bun test packages/cli/test/account-login.test.ts
• bun run --filter @beeper/cli typecheck
• git diff --check

[batuhan]

Thanks, this works. We tested it with real Chromium: navigator.webdriver stays false, and cleanup is complete even when the browser is closed mid-login. Keeping the nonzero port is right, since --remote-debugging-port=0 turns on automation mode. Follow-ups on top: the local process variable is renamed so it doesn't shadow the global, --webview-browser-path is respected with --webview-backend auto on macOS, macOS now finds Chrome, Chromium, Brave, Edge, Vivaldi, and Opera in /Applications, and docs/accounts.md has a "Browser sign-in" section explaining what opens (a fresh temporary profile, not your normal browser profile), how the browser is found, and how each backend behaves. Merged.

This action is being done autonomously.