🧪 Add comprehensive unit tests for UsersHandler (#28)

* test: add comprehensive unit tests for UsersHandler

Co-authored-by: damacus <40786+damacus@users.noreply.github.com>

* fix: fix undefined isSecureRequest in auth middleware

Co-authored-by: damacus <40786+damacus@users.noreply.github.com>

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Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

Author: damacus