feat: add support for recent request tracking in auth records

- Implemented `RecentRequestsSnapshot` in `Auth` to capture bucketed recent request data.
- Added new fields and methods to `Auth` for tracking request success and failure counts over time.
- Updated `/v0/management/auth-files` response to include recent request data for each auth record.
- Introduced unit tests to validate request tracking and snapshot generation logic.

internal/api/handlers/management/auth_files.go

@@ -388,6 +388,7 @@ func (h *Handler) buildAuthFileEntry(auth *coreauth.Auth) gin.H {
 		"source":         "memory",
 		"size":           int64(0),
 	}
+	entry["recent_requests"] = auth.RecentRequestsSnapshot(time.Now())
 	if email := authEmail(auth); email != "" {
 		entry["email"] = email
 	}