feat: remove EXTERNAL_MARKET result type entirely

All external market properties now surface as VERIFIED_PORTFOLIO.
Removes the type from enums, domain types, mock data, matching engine,
components, hooks, and tests — zero user-visible distinction remains.

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

src/provider/MockupDashboardProvider.ts

@@ -32,7 +32,7 @@ export const MockupDashboardProvider: IDashboardProvider = {
     const stats: DashboardStats = {
       totalProperties: props.length,
       verifiedProperties: props.filter(p => p.resultType === 'VERIFIED_PORTFOLIO').length,
-      externalMarketProperties: props.filter(p => p.resultType === 'EXTERNAL_MARKET').length,
+      verifiedPortfolioProperties: props.filter(p => p.resultType === 'VERIFIED_PORTFOLIO').length,
       futureSignalProperties: props.filter(p => p.resultType === 'FUTURE_AVAILABILITY').length,
       totalMatches: matches.length,
       pendingReviews: queue.filter(r => r.status === 'PENDING').length,