feat: F021 market intelligence & signal discovery

Signal domain types, mock data (8 signals), provider interface + MockupMarketIntelligenceProvider, marketIntelligenceService, TanStack Query hooks, 10 ops components (SignalInbox, MarketSignalCard, MarketSignalFilterBar, MarketSignalSkeleton, MarketSignalEmptyState, SignalConfidenceBadge, SourceReliabilityBadge, SensitivityWarningPanel, SignalConversionPanel, SignalEvidenceList), MarketIntelligence page wired into AppShell nav and App router.

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

src/services/marketIntelligenceService.ts

@@ -0,0 +1,41 @@
+import { MockupMarketIntelligenceProvider } from '../provider/MockupMarketIntelligenceProvider'
+import type { MarketSignal, MarketSignalFilters, SignalProcessingStatus } from '../domain/marketSignal'
+import type { ListResponse, ItemResponse } from './types'
+
+const provider = MockupMarketIntelligenceProvider
+
+export const marketIntelligenceService = {
+  async getSignals(filters?: MarketSignalFilters): Promise<ListResponse<MarketSignal>> {
+    const data = await provider.getSignals(filters)
+    return { data, meta: { total: data.length, page: 1, pageSize: data.length, hasMore: false } }
+  },
+
+  async getSignalDetail(id: string): Promise<ItemResponse<MarketSignal | null>> {
+    const data = await provider.getSignalById(id)
+    return { data }
+  },
+
+  async updateSignalStatus(
+    id: string,
+    status: SignalProcessingStatus,
+  ): Promise<ItemResponse<MarketSignal>> {
+    const data = await provider.updateSignalStatus(id, status)
+    return { data }
+  },
+
+  async convertToFutureSignal(
+    id: string,
+  ): Promise<ItemResponse<{ futureSignalId: string }>> {
+    const data = await provider.convertToFutureSignal(id)
+    return { data }
+  },
+
+  async linkSignalToEntity(
+    id: string,
+    entityType: 'property' | 'need',
+    entityId: string,
+  ): Promise<ItemResponse<MarketSignal>> {
+    const data = await provider.linkSignalToEntity(id, entityType, entityId)
+    return { data }
+  },
+}