fix: reliable cloud sync and connection pooling for Render live dashboard

contec_server.py

@@ -657,10 +657,39 @@ async def _persist_and_forward_bg(vitals, should_persist):
                     patient.patient_type = vitals.patient_type
                 if vitals.device_id:
                     patient.device_id = vitals.device_id
+            if patient:
+                if not vitals.patient_id or vitals.patient_id == "UNKNOWN":
+                    vitals.patient_id = patient.mrn or patient.patient_id
+                if not vitals.patient_name or vitals.patient_name == "Unknown":
+                    vitals.patient_name = patient.name
+                if not vitals.patient_gender and patient.gender:
+                    vitals.patient_gender = patient.gender
+                if not vitals.patient_dob and patient.dob:
+                    vitals.patient_dob = patient.dob
+                if not vitals.bed_id and patient.bed_id:
+                    vitals.bed_id = patient.bed_id
+                if not getattr(vitals, "patient_type", None) and getattr(patient, "patient_type", None):
+                    vitals.patient_type = patient.patient_type
+
+            # Backfill non-null vitals from device cache so REST forwarders always get complete vitals
+            cached = device_cache.get(vitals.device_id)
+            if cached:
+                if vitals.heart_rate is None and cached.heart_rate is not None:
+                    vitals.heart_rate = cached.heart_rate
+                if vitals.spo2 is None and cached.spo2 is not None:
+                    vitals.spo2 = cached.spo2
+                if vitals.systolic_bp is None and cached.systolic_bp is not None:
+                    vitals.systolic_bp = cached.systolic_bp
+                    vitals.diastolic_bp = cached.diastolic_bp
+                    vitals.map_bp = cached.map_bp
+                if vitals.respiratory_rate is None and cached.respiratory_rate is not None:
+                    vitals.respiratory_rate = cached.respiratory_rate
+                if vitals.temperature is None and cached.temperature is not None:
+                    vitals.temperature = cached.temperature
 
             reading = VitalReading(
                 device_id=vitals.device_id,
-                patient_id=vitals.patient_id,
+                patient_id=vitals.patient_id or (patient.mrn if patient else "UNKNOWN"),
                 timestamp=vitals.timestamp,
                 heart_rate=vitals.heart_rate,
                 spo2=vitals.spo2,