feat: Marktsignale KPI panel with adjustable radius (5/10/15/20 km)

Adds MarketKpis domain type with formula-based radius scaling, a MarketKpiPanel
component (vacancy rate, platform searches, avg vacancy duration, demand/supply
ratio — color-coded with interpretation badges), and integrates it at the top of
PropertyMarketSignalsTab. Demand/supply section labels now update with the
selected radius. Mock data covers all 5 existing market reports.

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

src/mock-data/propertyMarketSignals.ts

@@ -4,6 +4,14 @@ export const mockPropertyMarketSignals: MarketReport[] = [
   {
     propertyId: 'prop-001',
     generatedAt: '2025-05-18T08:00:00Z',
+    assetTypeLabel: 'Büro',
+    kpis: {
+      vacancyRatePct: 4.2,
+      activePlatformSearches: 14,
+      avgVacancyMonths: 4.2,
+      demandSupplyRatio: 2.3,
+      comparableListings: 3,
+    },
     signals: [
       {
         id: 'sig-001-1',
@@ -44,6 +52,14 @@ export const mockPropertyMarketSignals: MarketReport[] = [
   {
     propertyId: 'prop-007',
     generatedAt: '2025-05-18T08:00:00Z',
+    assetTypeLabel: 'Büro',
+    kpis: {
+      vacancyRatePct: 3.8,
+      activePlatformSearches: 11,
+      avgVacancyMonths: 3.5,
+      demandSupplyRatio: 2.8,
+      comparableListings: 1,
+    },
     signals: [
       {
         id: 'sig-007-1',
@@ -83,6 +99,14 @@ export const mockPropertyMarketSignals: MarketReport[] = [
   {
     propertyId: 'prop-008',
     generatedAt: '2025-05-18T08:00:00Z',
+    assetTypeLabel: 'Büro',
+    kpis: {
+      vacancyRatePct: 7.1,
+      activePlatformSearches: 7,
+      avgVacancyMonths: 6.0,
+      demandSupplyRatio: 1.4,
+      comparableListings: 4,
+    },
     signals: [
       {
         id: 'sig-008-1',
@@ -123,6 +147,14 @@ export const mockPropertyMarketSignals: MarketReport[] = [
   {
     propertyId: 'prop-012',
     generatedAt: '2025-05-18T08:00:00Z',
+    assetTypeLabel: 'Büro',
+    kpis: {
+      vacancyRatePct: 2.9,
+      activePlatformSearches: 22,
+      avgVacancyMonths: 2.8,
+      demandSupplyRatio: 3.4,
+      comparableListings: 2,
+    },
     signals: [
       {
         id: 'sig-012-1',
@@ -172,6 +204,14 @@ export const mockPropertyMarketSignals: MarketReport[] = [
   {
     propertyId: 'prop-014',
     generatedAt: '2025-05-18T08:00:00Z',
+    assetTypeLabel: 'Lager / Logistik',
+    kpis: {
+      vacancyRatePct: 5.5,
+      activePlatformSearches: 11,
+      avgVacancyMonths: 5.8,
+      demandSupplyRatio: 1.9,
+      comparableListings: 2,
+    },
     signals: [
       {
         id: 'sig-014-1',