feat: Implement poll() method for efficient device communication and update monitoring status retrieval

sfm/server.py

@@ -626,15 +626,20 @@ def device_monitor_status(
     """
     Read monitoring status from the device.
 
-    Returns is_monitoring bool, battery voltage, and memory usage (total + free bytes).
-    Battery and memory are only present when the unit is idle (not monitoring).
+    Uses poll() (POLL handshake only — no config/compliance reads) so the
+    request completes in ~2 seconds instead of ~15.  The full connect() was
+    causing false "idle" readings because the compliance+event sequence was
+    interacting with the device state before the 0x1C read.
+
+    Returns is_monitoring bool, battery voltage, and memory usage (total + free
+    bytes).  Battery and memory are only present when the unit is idle.
     """
     with _build_client(port=port, baud=baud, host=host, tcp_port=tcp_port) as client:
         try:
-            client.connect()
+            client.poll()
         except Exception as exc:
-            log.warning("monitor status connect retry: %s", exc)
-            client.connect()
+            log.warning("monitor status poll retry: %s", exc)
+            client.poll()
         status = client.get_monitor_status()
 
     result: dict = {"is_monitoring": status.is_monitoring}
@@ -663,10 +668,10 @@ def device_monitor_start(
     """
     with _build_client(port=port, baud=baud, host=host, tcp_port=tcp_port) as client:
         try:
-            client.connect()
+            client.poll()
         except Exception as exc:
-            log.warning("start monitoring connect retry: %s", exc)
-            client.connect()
+            log.warning("start monitoring poll retry: %s", exc)
+            client.poll()
         client.start_monitoring()
     return {"status": "started"}
 
@@ -685,10 +690,10 @@ def device_monitor_stop(
     """
     with _build_client(port=port, baud=baud, host=host, tcp_port=tcp_port) as client:
         try:
-            client.connect()
+            client.poll()
         except Exception as exc:
-            log.warning("stop monitoring connect retry: %s", exc)
-            client.connect()
+            log.warning("stop monitoring poll retry: %s", exc)
+            client.poll()
         client.stop_monitoring()
     return {"status": "stopped"}