Add endpoints to reset per-user octet counters without restarting the
proxy, enabling external tools to implement periodic (monthly/daily)
quota resets.
New endpoints:
- POST /v1/users/{username}/reset-octets — reset single user
- POST /v1/users/reset-octets — reset all users
Changes:
- stats/mod.rs: add reset_user_octets() and reset_all_user_octets()
- api/mod.rs: add route handlers for both endpoints
- api/model.rs: add ResetOctetsResponse and ResetAllOctetsResponse
- docs/API.md: document new endpoints
Closes#510