Add WHOIS stats to status page with adaptive fetcher improvements

- Add WHOIS Fetcher card showing fresh/stale/never-fetched ASN counts
- Display hourly success/error counts and current fetch interval
- Increase max WHOIS rate to 1/sec (down from 10 sec minimum)
- Select random stale ASN instead of oldest for better distribution
- Add index on whois_updated_at for query performance
- Track success/error timestamps for hourly stats
- Add GetWHOISStats database method for freshness statistics

internal/routewatch/app_integration_test.go

@@ -335,6 +335,19 @@ func (m *mockStore) UpdateASNWHOIS(ctx context.Context, update *database.ASNWHOI
 	return nil
 }
 
+// GetWHOISStats mock implementation
+func (m *mockStore) GetWHOISStats(ctx context.Context, staleThreshold time.Duration) (*database.WHOISStats, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	return &database.WHOISStats{
+		TotalASNs:    len(m.ASNs),
+		FreshASNs:    0,
+		StaleASNs:    0,
+		NeverFetched: len(m.ASNs),
+	}, nil
+}
+
 // UpsertLiveRouteBatch mock implementation
 func (m *mockStore) UpsertLiveRouteBatch(routes []*database.LiveRoute) error {
 	m.mu.Lock()