Generates an authentication system by running mix phx.gen.auth and then
applying Skua's flow-specific changes. The generated code is yours to edit.
mix skua.gen.auth --auth magic_link # default — Phoenix's magic-link flow
mix skua.gen.auth --auth otp # 6-digit one-time-code login
mix skua.gen.auth --auth password_otp # password + OTP, both on the login screen
mix skua.gen.auth --auth custom # stock phx.gen.auth, nothing extraFlags:
--otp-length(otp/password_otp) — code length, default 6 (8 recommended for high-value apps).--otp-expiry— code validity in minutes, default 10.
Idempotent: re-running detects an existing Accounts context and skips the
base generation.