Auth setup opens wrong Chrome profile — no way to select profile

[GuyFrimerman]

Problem

When running auth_manager.py setup, the browser opens with a default/empty Chrome profile rather than the user's preferred profile. On machines with multiple Chrome profiles (e.g., personal + work Google accounts), there's no way to control which profile is used for authentication.

This is related to #14 in spirit — the internal browser doesn't leverage the user's existing Chrome setup.

Reproduction

1. Have multiple Chrome profiles configured (e.g., personal + work accounts)
2. Run python scripts/run.py auth_manager.py setup
3. Browser opens with the wrong Google account or a blank profile
4. User must manually log in from scratch instead of reusing existing session
5. On first attempt, the auth flow timed out because the profile mismatch was unexpected

Environment

• macOS (Darwin 25.3.0)
• Python 3.14
• Multiple Chrome profiles (Default, Profile 1–Profile 6)
• Skill installed as git submodule, symlinked to .claude/skills/notebooklm

Proposed fix

Allow specifying a Chrome profile via:

• A --profile flag on auth_manager.py setup (e.g., --profile "Profile 2")
• Or a CHROME_PROFILE env var in .env
• Internally, pass user_data_dir and profile_directory to patchright's launch_persistent_context()

This would also help with the latency issues in #14, since reusing an existing profile means existing cookies/sessions are available.