fix: BerichtDialog, images, and add property number + floor/unit structure

- BerichtDialog: conditionally mount instead of always-mounted with
  open prop; starts in 'generating' state immediately on open
- Images: fix all 6 wrong VERIFIED_PORTFOLIO and EXTERNAL_MARKET photos
  to match spec per assetType (OFFICE/RETAIL/LOGISTICS/PRODUCTION/MIXED)
- Domain: add PropertyUnit interface + propertyNumber field to Property
- Mock data: propertyNumber + units[] for prop-001/007/012/013
- UI: Stockwerkstruktur section in Übersicht tab (floor/unit table with
  availability, tenant, area); Objekt-Nr. shown below key metrics

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

src/components/supply/PropertyMarketSignalsTab.tsx

@@ -98,33 +98,29 @@ function SignalCard({ signal }: { signal: PropertyMarketSignal }) {
 type PdfState = 'idle' | 'generating' | 'ready'
 
 interface BerichtDialogProps {
-  open: boolean
   onClose: () => void
   report: MarketReport | null
   propertyId: string
 }
 
-function BerichtDialog({ open, onClose, report, propertyId }: BerichtDialogProps) {
-  const [state, setState] = useState<PdfState>('idle')
+function BerichtDialog({ onClose, report, propertyId }: Omit<BerichtDialogProps, 'open'>) {
+  const [state, setState] = useState<PdfState>('generating')
   const [progress, setProgress] = useState(0)
   const timerRef = useRef<ReturnType<typeof setInterval> | null>(null)
 
   useEffect(() => {
-    if (!open) { setState('idle'); setProgress(0); return }
-    setState('generating')
-    setProgress(0)
     let p = 0
     timerRef.current = setInterval(() => {
       p += Math.random() * 18 + 8
       if (p >= 100) {
         p = 100
         clearInterval(timerRef.current!)
-        setTimeout(() => setState('ready'), 300)
+        setState('ready')
       }
       setProgress(Math.min(100, p))
     }, 200)
     return () => { if (timerRef.current) clearInterval(timerRef.current) }
-  }, [open])
+  }, [])
 
   function handleDownload() {
     const signals = report?.signals ?? []
@@ -152,7 +148,7 @@ function BerichtDialog({ open, onClose, report, propertyId }: BerichtDialogProps
   }
 
   return (
-    <Dialog open={open} onClose={state === 'generating' ? undefined : onClose} maxWidth="xs" fullWidth>
+    <Dialog open onClose={state === 'generating' ? undefined : onClose} maxWidth="xs" fullWidth>
       <DialogTitle sx={{ fontWeight: 700, fontSize: '1rem', pb: 1 }}>
         Bericht erstellen
       </DialogTitle>
@@ -289,12 +285,13 @@ export function PropertyMarketSignalsTab({ propertyId }: Props) {
         })
       )}
 
-      <BerichtDialog
-        open={dialogOpen}
-        onClose={() => setDialogOpen(false)}
-        report={report}
-        propertyId={propertyId}
-      />
+      {dialogOpen && (
+        <BerichtDialog
+          onClose={() => setDialogOpen(false)}
+          report={report}
+          propertyId={propertyId}
+        />
+      )}
     </Box>
   )
 }