On the T114, GPS_RESET (pin 38) is the same pin as PIN_3V3_EN.
MicroNMEALocationProvider::begin() sets pin 38 HIGH (powering the 3V3
rail) but stop() never set it back LOW, leaving the GPS module powered
even when disabled.
Assert reset pin in stop() to mirror begin(), and guard
_location->loop() behind gps_active check.
Fixesmeshcore-dev/MeshCore#1628
PacketQueue::add() silently dropped packets when the queue was at
capacity. The packet pointer was lost — never enqueued, never returned
to the unused pool. Each occurrence permanently shrank the 32-packet
pool until allocNew() returned NULL and the node went deaf. Return bool
from add() and free the packet back to the pool on failure.