obd-poller over the K-line via the Bluetooth ELM327; gnss publisher; elm_connected

obd-poller drops its CAN socket: the Z27AG answers OBD-II only on ISO 9141-2.
It holds a raw RFCOMM link to the ELM (no pairing, no root), fixes the protocol
(ATSP3) so nothing probes CAN, publishes the obd_* signals, and releases the
adapter after a minute of ECU silence so it can sleep.
gnss: gpsd's fix as yukart/gnss/<signal>. orin-status: elm_connected from BlueZ.
One native deploy script (deploy-native.sh BIN) behind the per-service ones;
/etc/default/yukart-elm holds the adapter's address.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DDwfd6Ki8UfG4hK6W5YpJz

Cargo.toml

@@ -2,7 +2,7 @@
 name = "svc-core"
 version = "0.1.0"
 edition = "2021"
-description = "Acquisition and processing cluster: recorder, decoder, orin-status and obd-poller now; can-bridge and gnss later"
+description = "Acquisition and processing cluster: recorder, decoder, gnss, orin-status and obd-poller now; can-bridge later"
 publish = false
 
 [[bin]]
@@ -21,6 +21,10 @@ path = "src/obd-poller/main.rs"
 name = "decoder"
 path = "src/decoder/main.rs"
 
+[[bin]]
+name = "gnss"
+path = "src/gnss/main.rs"
+
 [[bin]]
 name = "bus-bench"
 path = "src/bus-bench/main.rs"