milestone 26: upstream health answers for the selected period

src/tests.zig

@@ -75,6 +75,8 @@ comptime {
     _ = @import("cache/dns_cache.zig");
     _ = @import("server/rate_limiter.zig");
     _ = @import("storage/repositories/queries_repo.zig");
+    _ = @import("storage/repositories/upstream_history_repo.zig");
+    _ = @import("upstream/history.zig");
     _ = @import("storage/logger.zig");
     _ = @import("platform/statfs.zig");
     _ = @import("storage/disk_monitor.zig");