fix: align Project status enum to Prisma + cascade child records on listing delete

Project status was declared on the frontend as
UPCOMING/SELLING/HANDOVER/COMPLETED but the Prisma enum
ProjectDevelopmentStatus is PLANNING/UNDER_CONSTRUCTION/HANDOVER/
COMPLETED — CREATE failed with "status must be one of …". Aligned the
TypeScript union + PROJECT_STATUS_LABELS/COLORS, filter options on
/projects list, and both new + edit forms. Updated the
normalizeProjectDetail fallback and the du-an test spec to match.

Listings DELETE was blocked by FK references (Inquiry, SavedListing,
PriceHistory, Order, Transaction have no onDelete: Cascade in schema).
Wrapped the Prisma listing delete in a $transaction that removes the
child rows first, then the listing itself, so CRUD from the dashboard
actually lands instead of returning "Referenced record does not exist".

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/lib/du-an-server.ts

@@ -63,7 +63,7 @@ function normalizeProjectDetail(raw: unknown): ProjectDetail | null {
     id: String(r['id'] ?? ''),
     slug: String(r['slug'] ?? ''),
     name: String(r['name'] ?? ''),
-    status: (r['status'] as ProjectDetail['status']) ?? 'SELLING',
+    status: (r['status'] as ProjectDetail['status']) ?? 'PLANNING',
     developer,
     city: String(r['city'] ?? ''),
     district: String(r['district'] ?? ''),