Duration (minutes) and Buffer (minutes): slot length and gap between slots.
Capacity: max bookings per slot. If capacity is filled and overlap is disallowed, the slot is blocked.
Allow overlap: when enabled, bookings for the same slot can exceed capacity checks against other sessions.
Timezone: defaults to WordPress timezone; can be overridden per session.
Product override: WooCommerce product ID that replaces the global product when checkout is enabled.
Price / price-free: informational fields stored on the session (pricing is enforced by the Woo product).
Color, photographer name/role, avatar, description, location: used in Admin Center views.
Availability start/end: optional window that restricts the calendar to a date range.
Per-day schedule JSON: optional daily schedule for the session (per weekday) that replaces the global weekly schedule when set.