fix(db): add missing indexes, bound unbounded queries, parallelize admin queries

- Add 7 missing indexes: User(kycStatus, isActive, createdAt),
  Listing(createdAt, featuredUntil, expiresAt), Payment(createdAt)
- Add take:50 limit to unbounded findMediaByPropertyId and findByPropertyId
- Parallelize sequential queries in getUserDetail with Promise.all

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

prisma/schema.prisma

@@ -57,6 +57,9 @@ model User {
 
   @@index([phone])
   @@index([role])
+  @@index([kycStatus])
+  @@index([isActive])
+  @@index([createdAt])
 }
 
 enum OAuthProvider {
@@ -245,6 +248,9 @@ model Listing {
   @@index([propertyId])
   @@index([agentId])
   @@index([publishedAt])
+  @@index([createdAt])
+  @@index([featuredUntil])
+  @@index([expiresAt])
 }
 
 // =============================================================================
@@ -378,6 +384,7 @@ model Payment {
   @@index([transactionId])
   @@index([status])
   @@index([providerTxId])
+  @@index([createdAt])
 }
 
 // =============================================================================