Prefer current orthophoto source version

backend/app/services/source_freshness_service.py

@@ -81,6 +81,21 @@ def _latest_dataset(datasets: list[Dataset]) -> Dataset:
     )
 
 
+def _latest_source_version(policy: SourcePolicy, datasets: list[Dataset]) -> str | None:
+    versioned = [item for item in datasets if item.source_version]
+    if not versioned:
+        return None
+    if policy.refresh_policy == "rolling_snapshot":
+        named_current = [
+            item
+            for item in versioned
+            if any(token in (item.source_version or "").lower() for token in ("most_recent", "latest", "current"))
+        ]
+        if named_current:
+            return _latest_dataset(named_current).source_version
+    return _latest_dataset(versioned).source_version
+
+
 def _is_local_storage_path(storage_path: str) -> bool:
     normalized = storage_path.strip().lower()
     return bool(normalized) and "://" not in normalized and not normalized.startswith("/vsi")
@@ -225,7 +240,6 @@ class SourceFreshnessService:
                 next_review_at = None
                 reason = "Voor deze bron is nog geen expliciete publicatie- of controlecyclus vastgelegd."
                 recommended_action = "Classificeer de bron eerst als snapshot, jaargang, vaste editie, scenario, archief of lokaal."
-            latest = _latest_dataset(source_datasets)
             observed_values = {value for item in source_datasets if (value := _as_utc(item.observed_at)) is not None}
             temporal_keys = {item.temporal_series_key for item in source_datasets if item.temporal_series_key}
             items.append(
@@ -237,21 +251,7 @@ class SourceFreshnessService:
                     version_count=sum(len(versions_by_dataset.get(item.id, [])) for item in source_datasets),
                     latest_imported_at=_latest_datetime(item.imported_at for item in source_datasets),
                     latest_observed_at=_latest_datetime(item.observed_at for item in source_datasets),
-                    latest_source_version=next(
+                    latest_source_version=_latest_source_version(policy, source_datasets),
-                        (
-                            item.source_version
-                            for item in sorted(
-                                source_datasets,
-                                key=lambda value: (
-                                    _as_utc(value.observed_at) or datetime.min.replace(tzinfo=timezone.utc),
-                                    _as_utc(value.imported_at) or datetime.min.replace(tzinfo=timezone.utc),
-                                ),
-                                reverse=True,
-                            )
-                            if item.source_version
-                        ),
-                        latest.source_version,
-                    ),
                     refresh_policy=policy.refresh_policy,
                     review_interval_days=policy.review_interval_days,
                     next_review_at=next_review_at,

backend/tests/test_sprint221_source_freshness_audit.py

@@ -133,6 +133,30 @@ def test_source_freshness_requires_dataset_version_and_marks_temporal_series() -
     assert item.integrity.missing_version_count == 1
 
 
+def test_rolling_orthophoto_prefers_explicit_current_snapshot_over_historical_observation() -> None:
+    current = _dataset(
+        "digitaal_vlaanderen_orthophoto",
+        imported_at=NOW - timedelta(days=2),
+        observed_at=None,
+        source_version="most_recent_at_2026-07-14",
+    )
+    historical = _dataset(
+        "digitaal_vlaanderen_orthophoto",
+        imported_at=NOW - timedelta(days=1),
+        observed_at=datetime(2020, 6, 1, tzinfo=timezone.utc),
+        source_version="2020",
+    )
+
+    report = SourceFreshnessService.build_report(
+        current.project_id,
+        [current, historical],
+        [_version(current), _version(historical)],
+        now=NOW,
+    )
+
+    assert report.items[0].latest_source_version == "most_recent_at_2026-07-14"
+
+
 def test_source_freshness_route_returns_canonical_envelope(monkeypatch) -> None:
     from app.api.routes import datasets as dataset_routes