feat(investigations): add event impact and work-order feedback flows

Add isolated burst and pollution impact evidence, parallel work-order workflows, persisted notifications and graph updates.

Checkpoint current code. Known follow-ups remain for large pollution result previews and graceful geometry failure.

app/services/scada_normal_profile.py

@@ -19,9 +19,20 @@ def current_calibration(document: dict, start: datetime) -> dict | None:
     return None
 
 
+def pollution_signal(document: dict, event: dict) -> bool:
+    """Water-quality measurements have their own incident investigation workflow."""
+    if event.get("category") == "data_quality":
+        return False
+    devices = {item["device_id"]: item.get("device_type") for item in document.get("devices", [])}
+    ids = event.get("device_ids") or next((item.get("device_ids", [])
+        for item in (document.get("config") or {}).get("rules", [])
+        if item["rule_id"] == event.get("rule_id")), [])
+    return bool(ids) and all(devices.get(device) in {"quality", "water_quality"} for device in ids)
+
+
 def diagnostic_signal(document: dict, event: dict) -> bool:
     """Never revive a persisted fixed-percentage event as new diagnosis evidence."""
-    if event.get("category") == "data_quality":
+    if event.get("category") == "data_quality" or pollution_signal(document, event):
         return False
     if not weighted_diagnosis(document):
         return True