feat(listings): complete featured listings with payment, expiry, and Typesense boost

- Add `featuredPackage` column to Listing (3_days/7_days/30_days)
- Update ActivateFeaturedListingHandler to store package + emit listing.updated for Typesense re-index
- Add ListingFeaturedExpiredHandler in search module to re-index on featured expiry
- Add tier-weighted isFeatured boost in Typesense (30d=3, 7d=2, 3d=1)
- Update expiry cron to clear featuredPackage alongside featuredUntil
- Update admin and promote handlers to persist featuredPackage
- Add/update tests: activation (8 cases), featured-expired search handler

TEC-3070

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

prisma/migrations/20260421000000_add_featured_package/migration.sql

@@ -0,0 +1,5 @@
+-- AlterTable
+ALTER TABLE "Listing" ADD COLUMN "featuredPackage" TEXT;
+
+-- Backfill existing featured listings based on featuredUntil duration (best-effort)
+-- No backfill needed: featuredPackage is informational for new purchases only.

prisma/schema.prisma

@@ -407,6 +407,7 @@ model Listing {
   saveCount        Int             @default(0)
   inquiryCount     Int             @default(0)
   featuredUntil    DateTime?
+  featuredPackage  String?          /// "3_days" | "7_days" | "30_days"
   expiresAt        DateTime?
   publishedAt      DateTime?
   createdAt        DateTime        @default(now())