feat(formatters): frost handoff formatter + config wiring

Adds src/helper/formatters/frostFormatter.js — structured-envelope formatter parallel to the InfluxDB one. Produces dbase messages that a CoreSync collector can forward to FROST/SensorThings without coupling producing nodes to FROST HTTP details. Registered in formatters/index.js.

Config additions in 4 node schemas (machineGroupControl, measurement, pumpingStation, rotatingMachine) expose the new dbase format option in the editor.

Part of the CoreSync FROST handoff initiative — see superproject CORESYNC_FROST_INTERVIEW_HANDOFF.md.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/configs/measurement.json

@@ -120,6 +120,7 @@
                 "type": "enum",
                 "values": [
                     { "value": "influxdb", "description": "InfluxDB line-protocol payload (default)." },
+                    { "value": "frost", "description": "FROST/SensorThings CoreSync payload." },
                     { "value": "json", "description": "Raw JSON payload." },
                     { "value": "csv", "description": "CSV-formatted payload." }
                 ],
@@ -512,4 +513,4 @@
             }
         }
     }
-}
+}