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

app/services/burst_impact.py

@@ -17,7 +17,7 @@ GRADES = (
 
 def _head_factor(unit: Any) -> float | None:
     # Standard water head; unsupported or absent units must not become zero loss.
-    return {"m": 1.0, "meters": 1.0, "metres": 1.0,
+    return {"m": 1.0, "mtr": 1.0, "meters": 1.0, "metres": 1.0,
             "kpa": 1 / 9.80665, "psi": 6894.757293168 / 9806.65,
             "bar": 100000 / 9806.65, "mpa": 1000000 / 9806.65,
             "ft": 0.3048}.get(str(unit).strip().lower())

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)

app/services/operational_tasks.py

@@ -75,7 +75,7 @@ from app.domain.schemas.operational_task import (
 from app.domain.schemas.operational_data import TaskDataSnapshot, TaskDataSource
 from app.services.content_digest import digest
 from app.services.investigation_graph import adopt_legacy_investigation_graph, update_investigation_graph
-from app.services.operational_presentation import resolve_overlay
+from app.services.operational_presentation import resolve_overlay, validate_overlay_stage
 from app.services.operational_recovery import accept_completion, track_work_order
 from app.services.operational_scada_coverage import require_complete_scada_evidence
 from app.services import scada_presentation_coverage
@@ -1124,6 +1124,7 @@ class OperationalTaskService:
                     )
                     require(supplied == resolved, "OVERLAY_DATA_MISMATCH",
                             "Overlay data must match the immutable evidence snapshot", status=422)
+                validate_overlay_stage(resolved, command.narration.stage if command.narration else None)
                 payload["data"] = resolved
             metadata = {"task_id": str(task_id), "run_id": str(run["run_id"]),
                         "execution_generation": run["generation"], "command": payload}