feat: Mietvertrag-Mock für 50 % der Objekte (URL + Bezeichnung)

Jedes zweite Objekt bekommt per Post-Processing-Loop eine
leaseContractUrl (docs.wincasa.ch/…) + leaseContractName
(„Mietvertrag YYYY–YYYY") — ohne echten Inhalt, nur für die UI.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/mock-data/properties.ts

@@ -4489,6 +4489,15 @@ export const mockProperties: Property[] = [
 
 ]
 
+// Assign lease contract URLs to ~50 % of properties (every other one)
+mockProperties.forEach((p, i) => {
+  if (i % 2 !== 0) return
+  const startYear = p.leaseStartDate ? new Date(p.leaseStartDate).getFullYear() : 2020 + (i % 5)
+  const endYear   = p.leaseEndDate   ? new Date(p.leaseEndDate).getFullYear()   : startYear + 5
+  p.leaseContractUrl  = `https://docs.wincasa.ch/mietvertraege/${p.id}.pdf`
+  p.leaseContractName = `Mietvertrag ${startYear}–${endYear}`
+})
+
 // Assign images sequentially per pool so no two properties ever share the same image
 // (until pool wraps, which happens after ~12 properties per pool type)
 const _poolCounters: Record<string, number> = {}