fix: correct OpenWrt API metadata and earliest sample queries [CI]

backend/src/MoShiro.Backend.Application/Query/RowLoader.cs

@@ -79,16 +79,15 @@ public sealed class RowLoader
 
             if (earliest is null || at < earliest.Value + width)
             {
-                earliest = earliest is null ? at : Math.Min(earliest.Value, at);
+                earliest = at;
+                width = level.WidthMs();
             }
-
-            width = level.WidthMs();
         }
 
         long? hot = _hot.GetRange(agent, series, nowMs - Steps.Hour, nowMs + 10_000).Select(r => (long?)r.Key).Min();
         if (hot is { } h && (earliest is null || h < earliest.Value + width))
         {
-            earliest = earliest is null ? h : Math.Min(earliest.Value, h);
+            earliest = h;
         }
 
         return earliest;