revert: remove usage elapsed clock calibration

apps/aether-gateway/src/handlers/admin/observability/usage/summary_routes.rs

@@ -9,9 +9,9 @@ use aether_admin::observability::usage::{
     admin_usage_data_unavailable_response, admin_usage_has_fallback, admin_usage_is_failed,
     admin_usage_matches_search, admin_usage_matches_username, admin_usage_parse_ids,
     admin_usage_parse_limit, admin_usage_parse_offset, admin_usage_provider_key_name,
-    admin_usage_record_json, attach_usage_server_now_header,
-    build_admin_usage_active_requests_response, build_admin_usage_records_response,
-    build_admin_usage_summary_stats_response_from_summary, ADMIN_USAGE_DATA_UNAVAILABLE_DETAIL,
+    admin_usage_record_json, build_admin_usage_active_requests_response,
+    build_admin_usage_records_response, build_admin_usage_summary_stats_response_from_summary,
+    ADMIN_USAGE_DATA_UNAVAILABLE_DETAIL,
 };
 use aether_data::repository::users::StoredUserSummary;
 use aether_data_contracts::repository::{
@@ -338,15 +338,13 @@ fn build_admin_usage_records_response_with_attempt_flags(
         })
         .collect();
 
-    attach_usage_server_now_header(
-        Json(json!({
-            "records": records,
-            "total": total,
-            "limit": limit,
-            "offset": offset,
-        }))
-        .into_response(),
-    )
+    Json(json!({
+        "records": records,
+        "total": total,
+        "limit": limit,
+        "offset": offset,
+    }))
+    .into_response()
 }
 
 fn build_admin_usage_records_query(