The `:discordId` param validator on the five admin moderation routes used
`/^d{1,32}$/`, which matches 1-32 literal `d` characters instead of digits.
A real numeric Discord snowflake failed validation, so every
`/moderation/user/:discordId*` endpoint returned a 400 for valid input.
The backslash was dropped in a prior code-smell cleanup (12d50fd) that
intended `[0-9]` -> `\d`. Restore `\d` so the regex matches digits again.
Co-Authored-By: Claude <noreply@anthropic.com>
