fix(burst): recognize native pressure units and separate isolation impact

app/services/operational_presentation.py

@@ -104,3 +104,17 @@ def resolve_overlay(snapshot: TaskDataSnapshot, mode: str) -> dict:
             normalized["properties"]["weight"] = weight
         features.append(normalized)
     return {"type": "FeatureCollection", "features": features}
+
+
+def validate_overlay_stage(data: dict, stage: str | None) -> None:
+    """An event-impact claim must be supported by the saved scenario geometry."""
+    if stage != "event_impact":
+        return
+    features = data.get("features", [])
+    require(bool(features) and all(
+        (feature.get("properties") or {}).get("impact_phase") in {
+            "after_burst_before_intervention", "after_contamination_before_intervention",
+        } for feature in features
+    ), "OVERLAY_IMPACT_PHASE_MISMATCH",
+        "事件影响阶段须引用处置前情景覆盖；关阀及供水失源覆盖请使用 isolation_plan，不能替代不可用的事件降压结果",
+        status=422)