Answer token endpoint failures with the RFC 6749 error codes, and look up the UserInfo client by azp - #282

string `http://localhost/callback` has 4 occurrences, make it a constant (goconst)

string `wrong` has 2 occurrences, make it a constant (goconst)

string `unknownclient` has 2 occurrences, make it a constant (goconst)

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/cache@v4, actions/checkout@v4, actions/setup-go@v5, golangci/golangci-lint-action@v8. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/