Featureflip SDK Keys API

SDK keys within a resolved organization + project + environment — one level deeper thanEnvironmentsController. Every action resolves `{project}` (key-or-guid,scoped to the resolved org, with the service-token project allowlist forwarded) then`{env}` (key-or-guid, scoped to the resolved project) viaIPublicApiTenantResolver, mirroring FeatureFlagsController'sresolve-then-dispatch shape. Unlike `{project}`/`{env}`, `{sdkKey}` isguid-only — SDK keys have no key/slug of their own — resolved viaResolveSdkKeyIdAsync, which throws the samenot-found error for a non-guid segment as a genuinely missing key. Writes(create/update/revoke) require at least Member(RequireRole); a Viewer attempting one gets a 403`forbidden` envelope.Type is a bare string on the wire; Createparses it to SdkKeyType against a NAME allowlist(`Enum.TryParse` + `Enum.GetNames().Contains(...)`) rather than a bare`Enum.TryParse`/`Enum.IsDefined` pair — the latter would silently accept a numericstring (e.g. `"0"`) and resolve it to the first enum member. An unrecognized value throwsthe custom ValidationException BEFORE the environment is resolved or any commandis dispatched, mapped to a 400 `validation_failed` envelope byPublicApiExceptionFilterAttribute — same pattern asMapConditions's operator parse.The plaintext key returned by CreateSdkKeyResult is a one-time value — it isnever recoverable afterward, so unlike Create'sre-fetch-after-write pattern, Create builds its response directly from thecommand result rather than dispatching a follow-up query. List andGet return PublicSdkKeyResponse, which carries only`LastFourCharacters` — never the plaintext.