add car reservation feature

packages/database/prisma/schema.prisma

@@ -315,6 +315,11 @@ enum NotificationStatus {
   READ
 }
 
+enum CalendarBlockType {
+  MANUAL
+  MAINTENANCE
+}
+
 // ═══════════════════════════════════════════════════════════════
 // B2B — COMPANY SIDE
 // ═══════════════════════════════════════════════════════════════
@@ -481,9 +486,10 @@ model Vehicle {
   notes        String?
   isPublished  Boolean         @default(true)
 
-  reservations  Reservation[]
-  maintenance   MaintenanceLog[]
-  offerVehicles OfferVehicle[]
+  reservations    Reservation[]
+  maintenance     MaintenanceLog[]
+  offerVehicles   OfferVehicle[]
+  calendarBlocks  VehicleCalendarBlock[]
 
   createdAt DateTime @default(now())
   updatedAt DateTime @updatedAt
@@ -796,6 +802,23 @@ model MaintenanceLog {
   @@map("maintenance_logs")
 }
 
+model VehicleCalendarBlock {
+  id        String            @id @default(cuid())
+  vehicleId String
+  vehicle   Vehicle           @relation(fields: [vehicleId], references: [id], onDelete: Cascade)
+  startDate DateTime          @db.Date
+  endDate   DateTime          @db.Date
+  reason    String?
+  type      CalendarBlockType @default(MANUAL)
+
+  createdAt DateTime @default(now())
+  updatedAt DateTime @updatedAt
+
+  @@index([vehicleId])
+  @@index([vehicleId, startDate, endDate])
+  @@map("vehicle_calendar_blocks")
+}
+
 // ═══════════════════════════════════════════════════════════════
 // DOCUMENTS — CONTRACT SETTINGS
 // ═══════════════════════════════════════════════════════════════