refactor: use @heroku/sdk for auth commands

[erika-wallace]

Summary

Migrates the following auth commands to @heroku/sdk:

• auth/whoami
• auth/token
• auth/2fa
• auth/login

Details

• auth/whoami: Migrated GET /account call to platform.account.info()
• auth/token: Migrated GET /oauth/authorizations call to platform.oauthAuthorization.list()
• auth/2fa: Migrated GET /account call to platform.account.info()
• auth/login: Migrated GET /account call to platform.account.info() (login flow itself remains with APIClient.login())

Not migrated

• auth/logout: No HTTP API calls to migrate (only uses APIClient.logout() and local credential management)
• auth/2fa/disable: Command just errors out; no API calls

Testing

Notes:
The SDK uses heroku-fetch to make API calls, which looks for a netrc file. Therefore, we must login with HEROKU_NETRC_WRITE=true.

Steps:

1. Pull down this branch
2. npm i && npm run build
3. ./bin/run logout
4. HEROKU_NETRC_WRITE=true ./bin/run login — Outputs "logged in as email"
5. ./bin/run whoami — Outputs "email"
6. ./bin/run auth:token — Outputs "token"
7. ./bin/run auth:2fa — Outputs "two-factor authentication is enabled/not enabled"

Cleanup:

• ./bin/run logout

Related Issues

GUS work item: W-23373474