fix(subscriptions): atomic UsageRecord metering to prevent quota bypass

- Add @@unique([subscriptionId, metric, periodStart, periodEnd]) constraint
  to UsageRecord model with corresponding migration
- Replace racy findFirst+update/create pattern with Prisma upsert using
  INSERT ON CONFLICT DO UPDATE SET count = count + delta
- Fix CheckQuotaHandler to use period-scoped findUnique instead of
  unscoped findFirst, preventing stale cross-period reads
- Update tests to reflect atomic upsert pattern

Closes GOO-4

Co-Authored-By: Paperclip <noreply@paperclip.ing>

prisma/schema.prisma

@@ -265,6 +265,9 @@ enum PropertyType {
   LAND
   OFFICE
   SHOPHOUSE
+  ROOM_RENTAL
+  CONDOTEL
+  SERVICED_APARTMENT
 }
 
 enum TransactionType {
@@ -757,6 +760,7 @@ model UsageRecord {
   periodStart    DateTime
   periodEnd      DateTime
 
+  @@unique([subscriptionId, metric, periodStart, periodEnd])
   @@index([subscriptionId, metric])
 }
 
@@ -1064,10 +1068,10 @@ model IndustrialPark {
   remainingAreaHa   Float
   tenantCount       Int                                  @default(0)
   establishedYear   Int?
-  landRentUsdM2Year Float?
-  rbfRentUsdM2Month Float?
-  rbwRentUsdM2Month Float?
-  managementFeeUsd  Float?
+  landRentUsdM2Year Decimal?                             @db.Decimal(18, 4)
+  rbfRentUsdM2Month Decimal?                             @db.Decimal(18, 4)
+  rbwRentUsdM2Month Decimal?                             @db.Decimal(18, 4)
+  managementFeeUsd  Decimal?                             @db.Decimal(18, 4)
   infrastructure    Json? // { electricity, water, wastewater, telecom, roads, fire }
   connectivity      Json? // { nearestPort, airport, highway, railway, seaport }
   incentives        Json? // { taxHoliday, importDuty, landRentReduction, specialZone }
@@ -1121,10 +1125,10 @@ model IndustrialListing {
   hasMezzanine     Boolean                 @default(false)
   hasOfficeArea    Boolean                 @default(false)
   officeAreaM2     Float?
-  priceUsdM2       Float?
+  priceUsdM2       Decimal?                @db.Decimal(18, 4)
   pricingUnit      String? // "usd/m2/month", "usd/m2/year"
-  totalLeasePrice  Float?
-  managementFee    Float?
+  totalLeasePrice  Decimal?                @db.Decimal(18, 4)
+  managementFee    Decimal?                @db.Decimal(18, 4)
   depositMonths    Int?
   minLeaseYears    Int?
   maxLeaseYears    Int?