Add rate plans, room stay rates, and payments ledger

AGENTS.md

@@ -48,14 +48,16 @@ Security/Auth
 Domain entities
 - Property: code, name, addressText, emailAddresses, otaAliases, allowedTransportModes.
 - AppUser (global, superAdmin), PropertyUser (roles per property).
-- RoomType: code/name/occupancy + otaAliases.
+- RoomType: code/name/occupancy + otaAliases + defaultRate.
 - Room: roomNumber, floor, hasNfc, active, maintenance, notes.
 - Booking: status, expected check-in/out, emailAuditPdfUrl, transportMode.
 - Guest (property-scoped).
-- RoomStay.
+- RoomStay (rate fields stored on stay).
 - RoomStayChange (idempotent room move).
 - IssuedCard (cardId, cardIndex, issuedAt, expiresAt, issuedBy, revokedAt).
 - PropertyCardCounter (per-property cardIndex counter).
+- RatePlan + RateCalendar.
+- Payment (ledger).
 - GuestDocument (files + AI-extracted json).
 - GuestVehicle (property-scoped vehicle numbers).
 - InboundEmail (audit PDF + raw EML, extracted json, status).
@@ -88,6 +90,7 @@ Rooms / inventory
 Room types
 - POST /properties/{propertyId}/room-types
 - GET /properties/{propertyId}/room-types
+- GET /properties/{propertyId}/room-types/{roomTypeCode}/rate?date=YYYY-MM-DD&ratePlanCode=optional
 - PUT /properties/{propertyId}/room-types/{roomTypeId}
 - DELETE /properties/{propertyId}/room-types/{roomTypeId}
 
@@ -117,6 +120,23 @@ Guest APIs
 - /properties/{propertyId}/guests/search?phone=... or ?vehicleNumber=...
 - /properties/{propertyId}/guests/{guestId}/vehicles (add vehicle)
 
+Room stays
+- POST /properties/{propertyId}/room-stays/{roomStayId}/change-rate
+
+Rate plans
+- POST /properties/{propertyId}/rate-plans
+- GET /properties/{propertyId}/rate-plans
+- PUT /properties/{propertyId}/rate-plans/{ratePlanId}
+- DELETE /properties/{propertyId}/rate-plans/{ratePlanId}
+- POST /properties/{propertyId}/rate-plans/{ratePlanId}/calendar
+- GET /properties/{propertyId}/rate-plans/{ratePlanId}/calendar?from=YYYY-MM-DD&to=YYYY-MM-DD
+- DELETE /properties/{propertyId}/rate-plans/{ratePlanId}/calendar/{rateDate}
+
+Payments
+- POST /properties/{propertyId}/bookings/{bookingId}/payments
+- GET /properties/{propertyId}/bookings/{bookingId}/payments
+- GET /properties/{propertyId}/bookings/{bookingId}/balance
+
 Guest documents
 - /properties/{propertyId}/guests/{guestId}/documents (upload/list)
 - /properties/{propertyId}/guests/{guestId}/documents/{documentId}/file