G6: N09 — add command wrappers for orphaned CommandType entries

Why: Five CommandType enum entries had no user-facing SDK method:
SEND_RAW_DATA (25), HAS_CONNECTION (28), GET_CONTACT_BY_KEY (30),
GET_TUNING_PARAMS (43), FACTORY_RESET (51). Added send_raw_data() in
MessagingCommands, has_connection()/get_tuning()/request_factory_reset()/
confirm_factory_reset() in DeviceCommands, get_contact_by_key() in
ContactCommands. FACTORY_RESET uses a two-step token pattern as a
Python-side safety measure against accidental invocation.

Refs: Forensics report finding N09 (also N03 for get_tuning)

src/meshcore/commands/contact.py

@@ -185,6 +185,24 @@ class ContactCommands(CommandHandlerBase):
         data = b"\x3B"
         return await self.send(data, [EventType.AUTOADD_CONFIG, EventType.ERROR])
 
+    async def get_contact_by_key(self, pubkey: bytes) -> Event:
+        """N09: Retrieve a single contact by its public key (CMD 30).
+
+        Args:
+            pubkey: 32-byte public key of the contact.
+
+        Returns:
+            Event with the contact data (same format as CONTACT/NEXT_CONTACT),
+            or ERROR if not found.
+        """
+        if not isinstance(pubkey, (bytes, bytearray)):
+            raise TypeError("pubkey must be bytes-like")
+        # Truncate or pad to 32 bytes
+        key_bytes = bytes(pubkey[:32])
+        logger.debug(f"Getting contact by key: {key_bytes.hex()}")
+        data = b"\x1e" + key_bytes
+        return await self.send(data, [EventType.NEXT_CONTACT, EventType.ERROR])
+
     async def get_advert_path(self, key: DestinationType) -> Event:
         key_bytes = _validate_destination(key, prefix_length=32)
         logger.debug(f"getting advert path for: {key} {key_bytes.hex()}")

src/meshcore/commands/device.py

@@ -4,6 +4,7 @@ from hashlib import sha256
 from typing import Optional
 
 from ..events import Event, EventType
+from ..packets import CommandType
 from .base import CommandHandlerBase, DestinationType, _validate_destination
 
 logger = logging.getLogger("meshcore")
@@ -273,20 +274,89 @@ class DeviceCommands(CommandHandlerBase):
 
         return await self.sign_finish(timeout=timeout, data_size=len(data))
 
+    async def has_connection(self) -> Event:
+        """N09: Check if the device has an active connection (CMD 28).
+
+        Returns:
+            Event with a 1-byte response indicating connection status,
+            or ERROR.
+        """
+        logger.debug("Checking device connection status")
+        return await self.send(b"\x1c", [EventType.OK, EventType.ERROR])
+
+    async def get_tuning(self) -> Event:
+        """N03/N09: Request current tuning parameters (CMD_GET_TUNING_PARAMS = 43).
+
+        Firmware responds with RESP_CODE_TUNING_PARAMS (23): 9 bytes containing
+        rx_delay (4 bytes LE) and airtime_factor (4 bytes LE).
+
+        Returns:
+            Event of type TUNING_PARAMS with rx_delay and airtime_factor,
+            or ERROR.
+        """
+        logger.debug("Getting tuning parameters")
+        return await self.send(b"\x2b", [EventType.TUNING_PARAMS, EventType.ERROR])
+
+    async def request_factory_reset(self) -> str:
+        """N09: Request a factory reset token (step 1 of 2).
+
+        This method returns a confirmation token string. Pass it to
+        ``confirm_factory_reset(token)`` to actually execute the reset.
+        The two-step pattern is a Python-side safety measure; the firmware
+        itself has no token verification.
+
+        Returns:
+            A confirmation token string to pass to confirm_factory_reset().
+        """
+        import secrets
+        token = secrets.token_hex(8)
+        logger.warning(
+            "Factory reset requested. Call confirm_factory_reset('%s') to proceed. "
+            "This will ERASE ALL DATA on the device.", token
+        )
+        # Store the token on the instance for validation
+        self._factory_reset_token = token
+        return token
+
+    async def confirm_factory_reset(self, token: str) -> Event:
+        """N09: Execute factory reset after token confirmation (step 2 of 2).
+
+        Args:
+            token: The token returned by request_factory_reset().
+
+        Returns:
+            Event with OK or ERROR.
+
+        Raises:
+            ValueError: If the token does not match.
+        """
+        expected = getattr(self, "_factory_reset_token", None)
+        if expected is None or token != expected:
+            raise ValueError(
+                "Invalid or expired factory reset token. "
+                "Call request_factory_reset() first."
+            )
+        self._factory_reset_token = None  # Consume the token
+        logger.warning("Executing factory reset — all device data will be erased")
+        return await self.send(b"\x33", [EventType.OK, EventType.ERROR])
+
     async def get_stats_core(self) -> Event:
         logger.debug("Getting core statistics")
-        # CMD_GET_STATS (56) + STATS_TYPE_CORE (0)
-        return await self.send(b"\x38\x00", [EventType.STATS_CORE, EventType.ERROR])
+        # R04: Use CommandType enum instead of literal bytes
+        cmd = bytes([CommandType.GET_STATS.value, 0x00])  # GET_STATS + STATS_TYPE_CORE
+        return await self.send(cmd, [EventType.STATS_CORE, EventType.ERROR])
 
     async def get_stats_radio(self) -> Event:
         logger.debug("Getting radio statistics")
-        # CMD_GET_STATS (56) + STATS_TYPE_RADIO (1)
-        return await self.send(b"\x38\x01", [EventType.STATS_RADIO, EventType.ERROR])
+        # R04: Use CommandType enum instead of literal bytes
+        cmd = bytes([CommandType.GET_STATS.value, 0x01])  # GET_STATS + STATS_TYPE_RADIO
+        return await self.send(cmd, [EventType.STATS_RADIO, EventType.ERROR])
 
     async def get_stats_packets(self) -> Event:
         logger.debug("Getting packet statistics")
-        # CMD_GET_STATS (56) + STATS_TYPE_PACKETS (2)
-        return await self.send(b"\x38\x02", [EventType.STATS_PACKETS, EventType.ERROR])
+        # R04: Use CommandType enum instead of literal bytes
+        cmd = bytes([CommandType.GET_STATS.value, 0x02])  # GET_STATS + STATS_TYPE_PACKETS
+        return await self.send(cmd, [EventType.STATS_PACKETS, EventType.ERROR])
 
     async def get_allowed_repeat_freq(self) -> Event:
         logger.debug("Getting allowed repeat freqs")