v1.0.14 - fix missing voltage sensor

Fix: voltage (and other fields) showing as Unavailable after connect

Root cause: The Junctek app sends a writeData("9ae0") command 1 second after subscribing to BLE notifications. This causes the device to emit a complete data flush, including c0 (voltage). Without this request, the device sends an incomplete set of fields spontaneously and voltage is never transmitted.

Evidence: Packet log analysis showed 183 consecutive packets with zero c0 (voltage) frames after upgrading to v1.0.13. The v1.0.12 b0 write was not the cause — it worked correctly (device echoed back the ack) — but the missing initial poll meant voltage never appeared.

Fix: After start_notify succeeds, a background task waits 1 second then sends bb9ae065ee (the framed 9ae0 poll command) to the write characteristic. This mirrors the app's behaviour exactly.

Note: Temperature (d9) remains Unavailable unless an external NTC probe is physically connected — that is correct and unchanged.