Reads %USERPROFILE%\.claude\.credentials.json (or ~/.claude/.credentials.json),
extracts the access and refresh tokens, stores them encrypted in Wraith's vault.
Works when Wraith's own OAuth exchange fails. If Claude Code is authenticated
on the same machine, Wraith piggybacks on the existing token.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>