Picking sensors & pin validation

When you add devices to a gateway, Synacl validates the pins you assign so two sensors don't collide.

• As you pick a protocol and pins, the recommender suggests free, compatible pins for that board.
• If you assign a pin already used (or one that can't do the job — e.g. a non-ADC pin for analog), you'll get a warning before saving.
• The gateway reports its capabilities so only compatible options are offered.

This prevents the most common field mistake — two devices fighting over one pin. After saving, the gateway syncs the new sensor config automatically.

On gateways with Ethernet support, six pins (4, 5, 18, 19, 23, 35) are reserved for the W5500 module whenever its network mode isn't Off — the picker refuses those pins for other sensors while Ethernet is in use.