Release v0.1.9: enforce Photos API boundary and finalize Server migration

tests/test_interval_schedule.py

@@ -0,0 +1,30 @@
+from datetime import UTC, datetime, timedelta
+
+import pytest
+from pydantic import ValidationError
+
+from pigway_frame_flow.errors import FlowError
+from pigway_frame_flow.models import Schedule
+from pigway_frame_flow.scheduler.engine import next_run
+
+
+@pytest.mark.parametrize("minutes", [1, 7, 60, 120, 420, 10080])
+def test_interval_crosses_calendar_boundaries(minutes):
+    start = datetime(2026, 10, 16, 23, 58, tzinfo=UTC)
+    schedule = Schedule(type="interval", interval_minutes=minutes)
+    first = datetime.fromisoformat(next_run(schedule, start))
+    assert first == start + timedelta(minutes=minutes)
+    assert datetime.fromisoformat(next_run(schedule, first)) == first + timedelta(
+        minutes=minutes
+    )
+
+
+@pytest.mark.parametrize("minutes", [0, -1, 10081])
+def test_invalid_interval(minutes):
+    with pytest.raises(ValidationError):
+        Schedule(type="interval", interval_minutes=minutes)
+
+
+def test_missing_interval_fails():
+    with pytest.raises(FlowError):
+        next_run(Schedule(type="interval"))