Validation of a player's order now applies every command against a
transient game-state snapshot and records the per-command outcome
(cmdApplied, cmdErrorCode) in each command's meta. The order is
persisted even when some commands are rejected, and the response is
202 + UserGamesOrder so clients can surface the partial failure
without the chain collapsing into "downstream service is unavailable".
Pkg/error consts are reshelved onto three explicit ranges with a
package doc and helpers (IsInternalCode/IsInputCode/IsGameStateCode):
1xxx internal/server (500/501), 2xxx structural input (400), 3xxx
game-state per-command rejection (400 when escaping HTTP, otherwise
recorded as cmdErrorCode). Two pre-existing typos fixed mechanically
(ErrBeakGroupNumberNotEnough -> ErrBreakGroupNumberNotEnough,
ErrRaceExinct -> ErrRaceExtinct) along with all callsites.
Engine errorResponse maps *GenericError by shelf rather than mapping
everything to 500. The Quit-not-last structural check in
Controller.ValidateOrder is preserved and its type assertion fixed
(was a value assertion against a pointer-typed command, so the check
silently never fired).
Backend, gateway and UI are unchanged — they were already correct on
the 202 path; only the engine collapsing per-command rejection into
500 was needed.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Ilia Denisov