tests: rework the actually useful tests to live in the integration crate

crates/irtt-stats/src/normalization.rs

@@ -218,43 +218,3 @@ fn duration_ns_i128(duration: Duration) -> i128 {
 fn signed_duration_ns(duration: SignedDuration) -> i128 {
     duration.as_nanos()
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn system_time_before_epoch_is_supported() {
-        let before = UNIX_EPOCH - Duration::from_nanos(7);
-        assert_eq!(system_time_ns(before), Some(-7));
-        let after = UNIX_EPOCH + Duration::from_nanos(7);
-        assert_eq!(system_time_ns(after), Some(7));
-        let now = SystemTime::now();
-        assert!(system_time_ns(now).is_some());
-    }
-
-    #[test]
-    fn loss_windowing_timestamp_is_clamped_to_its_own_sent_at() {
-        let base = Instant::now();
-        let sent_at = ClientTimestamp {
-            mono: base + Duration::from_millis(50),
-            wall: UNIX_EPOCH + Duration::from_millis(50),
-        };
-        // The pre-send-anchored `timeout_at` can precede this same probe's
-        // own post-send `sent_at` when probe_timeout is small relative to
-        // the send-call duration (see irtt-client's AGENTS.md). Rolling-
-        // window eviction assumes non-decreasing event timestamps, so the
-        // windowing `at()` must not regress behind the probe's own Sent
-        // event even though the public `timeout_at` field legitimately can.
-        let timeout_at = base + Duration::from_millis(10);
-
-        let event = ClientEvent::EchoLoss {
-            seq: 0,
-            sent_at,
-            timeout_at,
-        };
-
-        let normalized = normalize_event(&event).expect("loss event normalizes");
-        assert_eq!(normalized.at(), sent_at.mono);
-    }
-}