feat: registrationBegin method without email;

fix: missing sqlc query parameter name;
feat: util for generating security codes;
feat: enums package

sqlc/query.sql

@@ -94,8 +94,8 @@ WHERE users.username = $1;
 --: Confirmation Code Object {{{
 
 ;-- name: CreateConfirmationCode :one
-INSERT INTO confirmation_codes(user_id, code_type, code_hash, expires_at)
-VALUES ($1, $2, crypt($3, gen_salt('bf')), $4) RETURNING *;
+INSERT INTO confirmation_codes(user_id, code_type, code_hash)
+VALUES ($1, $2, crypt(@code::text, gen_salt('bf'))) RETURNING *;
 
 ;-- name: GetConfirmationCodeByCode :one
 SELECT * FROM confirmation_codes