fix(db): truncate downstream tables before services dedup to avoid FK violation

TRUNCATE appointments, invoices, invoice_line_items, invoice_tip_splits,
and grooming_visit_logs CASCADE before the services dedup DELETE to prevent
FK violations from appointments created by previous seed runs.

Fixes: GRO-365

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

packages/db/src/seed.ts

@@ -423,6 +423,9 @@ async function seed() {
   }
   console.log(`✓ Created ${allStaff.length} staff (1 manager, 1 receptionist, 3 groomers, 3 bathers)`);
 
+  // Truncate downstream tables before services dedup to avoid FK violation
+  await db.execute(sql`TRUNCATE appointments, invoices, invoice_line_items, invoice_tip_splits, grooming_visit_logs CASCADE`);
+
   // ── Services ──
   // Deduplicate existing services (keep lowest id per name) before inserting.
   await db.execute(sql`