Added a roam auth command that handles the full OAuth authorization flow for Roam Research. It prompts for client credentials, opens the browser for authorization, spins up a local callback server to receive the auth code, and exchanges it for an access token. The token gets stored in the config for use by future Roam commands.

Also added a few more git commands (git status, git grep, git log) to the permissions allow list so Claude Code can use them without prompting.