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/PropertyDetailView.tsx

@@ -20,7 +20,7 @@ import { useOfferWizardStore } from '../../stores/offerWizardStore'
 import { PropertyMap } from '../shared'
 import { NeedMatchCard } from './NeedMatchCard'
 import { PropertyMarketSignalsTab } from './PropertyMarketSignalsTab'
-import type { Property, UpdatePropertyInput } from '../../domain/property'
+import type { Property, PropertyUnit, UpdatePropertyInput } from '../../domain/property'
 import type { PropertyNeedMatch } from '../../domain/match'
 import { usePropertyById } from '../../hooks/useProperties'
 import { PropertyDetailSkeleton } from './PropertyDetailSkeleton'
@@ -90,7 +90,7 @@ function OverviewPanel({ p, editing, draft, onDraftChange }: OverviewPanelProps)
   return (
     <Box>
       {/* Key metrics */}
-      <Box sx={{ display: 'grid', gridTemplateColumns: 'repeat(3, 1fr)', gap: 1.5, mb: 2.5 }}>
+      <Box sx={{ display: 'grid', gridTemplateColumns: 'repeat(3, 1fr)', gap: 1.5, mb: 0.75 }}>
         {[
           { label: 'Fläche', value: `${p.areaSqm.toLocaleString('de-CH')} m²` },
           { label: 'CHF/m²/Jahr', value: rentLabel },
@@ -104,6 +104,11 @@ function OverviewPanel({ p, editing, draft, onDraftChange }: OverviewPanelProps)
           </Box>
         ))}
       </Box>
+      {p.propertyNumber && (
+        <Typography variant="caption" sx={{ color: '#94a3b8', mb: 2, display: 'block' }}>
+          Objekt-Nr. {p.propertyNumber}
+        </Typography>
+      )}
 
       {/* Description */}
       {editing ? (
@@ -177,11 +182,44 @@ function OverviewPanel({ p, editing, draft, onDraftChange }: OverviewPanelProps)
         </FieldGrid>
       )}
 
+      {/* Floor / unit structure */}
+      {p.units && p.units.length > 0 && (
+        <>
+          <Divider sx={{ my: 2 }} />
+          <SectionTitle title="Stockwerkstruktur" />
+          <Box sx={{ border: '1px solid #e2e8f0', borderRadius: 1.5, overflow: 'hidden', mb: 2 }}>
+            {/* header */}
+            <Box sx={{ display: 'grid', gridTemplateColumns: '80px 90px 1fr 90px', bgcolor: '#f8fafc', px: 1.5, py: 0.75, borderBottom: '1px solid #e2e8f0' }}>
+              {['Stockwerk', 'Einheit', 'Mieter / Status', 'Fläche'].map(h => (
+                <Typography key={h} variant="caption" sx={{ fontWeight: 600, color: '#64748b', fontSize: '0.65rem', textTransform: 'uppercase' }}>{h}</Typography>
+              ))}
+            </Box>
+            {p.units.map((u: PropertyUnit, i: number) => (
+              <Box key={u.id} sx={{ display: 'grid', gridTemplateColumns: '80px 90px 1fr 90px', px: 1.5, py: 0.875, borderBottom: i < p.units!.length - 1 ? '1px solid #f1f5f9' : 'none', alignItems: 'center' }}>
+                <Typography variant="caption" sx={{ fontWeight: 600, color: '#0f172a' }}>
+                  {u.floorLevel === 0 ? 'EG' : u.floorLevel < 0 ? `UG${Math.abs(u.floorLevel)}` : `${u.floorLevel}.OG`}
+                </Typography>
+                <Typography variant="caption" sx={{ color: '#374151' }}>{u.unitLabel ?? '–'}</Typography>
+                <Box sx={{ display: 'flex', alignItems: 'center', gap: 0.75 }}>
+                  {u.available ? (
+                    <Chip label="Frei" size="small" sx={{ height: 16, fontSize: '0.6rem', bgcolor: '#f0fdf4', color: '#166534', border: '1px solid #bbf7d0' }} />
+                  ) : (
+                    <Typography variant="caption" sx={{ color: '#64748b' }} noWrap>{u.currentTenant ?? 'Vermietet'}</Typography>
+                  )}
+                </Box>
+                <Typography variant="caption" sx={{ color: '#374151', textAlign: 'right' }}>{u.areaSqm.toLocaleString('de-CH')} m²</Typography>
+              </Box>
+            ))}
+          </Box>
+        </>
+      )}
+
       <Divider sx={{ my: 2 }} />
 
       {/* Object details */}
       <SectionTitle title="Objekt & Lage" />
       <FieldGrid>
+        {p.propertyNumber && <Field label="Objekt-Nr." value={p.propertyNumber} />}
         <Field label="Objekttyp" value={getAssetTypeLabel(p.assetType)} />
         <Field label="Etage" value={p.hardFacts?.floor ?? p.floorLevel} />
         <Field label="Ausbaustandard" value={p.hardFacts?.fitOut} />