Platform-specific availability windows

Currently, availability windows (how far in advance guests can book) are set at the property level and apply to all connected listings. This creates issues when different platforms have different policies or requirements.

For example, a host may want Houfy to be available 15 months in advance, while Airbnb is limited to 3 months due to their cancellation policies.

The request is to allow hosts to configure the availability window independently for each connected platform.