refactor(clients): rebuild detail tabs + columns for new data model

- ClientData in client-detail.tsx now reflects the stripped shape from
  Task 8.2 (drop companyName/isProxy/proxy*/yacht*/berthSizeDesired) and
  gains yachts / companies / activeReservations arrays.
- client-tabs.tsx: Overview trimmed (personal, contacts, source, tags);
  three new count-badged tabs (Yachts, Companies, Reservations).
- New client-yachts-tab.tsx renders owned yachts + Add yacht CTA (TODO:
  YachtForm preset-owner wiring for v2).
- New client-companies-tab.tsx renders memberships with Primary badge and
  since-date; management still lives on the company detail page.
- New client-reservations-tab.tsx maps activeReservations into ReservationRow
  shape and delegates to <ReservationList showBerth />.
- client-columns.tsx drops companyName column (TODO: add Yachts count +
  Primary company once list endpoint joins those).
- client-filters.tsx drops isProxy filter.
- Wire realtime invalidations for yacht:ownership_transferred,
  company_membership:added/ended, and berth_reservation:*.

src/components/clients/client-reservations-tab.tsx

@@ -0,0 +1,51 @@
+'use client';
+
+import { ReservationList, type ReservationRow } from '@/components/reservations/reservation-list';
+
+interface ClientReservationsTabProps {
+  clientId: string;
+  activeReservations: Array<{
+    id: string;
+    berthId: string;
+    yachtId: string;
+    startDate: string | Date;
+    tenureType: string;
+    status: string;
+  }>;
+}
+
+export function ClientReservationsTab({
+  clientId,
+  activeReservations,
+}: ClientReservationsTabProps) {
+  const rows: ReservationRow[] = activeReservations.map((r) => ({
+    id: r.id,
+    berthId: r.berthId,
+    portId: '', // not rendered by ReservationList
+    clientId,
+    yachtId: r.yachtId,
+    status: r.status as ReservationRow['status'],
+    startDate: typeof r.startDate === 'string' ? r.startDate : r.startDate.toISOString(),
+    endDate: null,
+    tenureType: r.tenureType,
+    contractFileId: null,
+    notes: null,
+    createdAt: '',
+  }));
+
+  return (
+    <div className="space-y-4">
+      <div>
+        <h3 className="text-sm font-medium">Active reservations</h3>
+        <p className="text-xs text-muted-foreground mt-0.5">
+          Showing currently active reservations. History is coming soon.
+        </p>
+      </div>
+      <ReservationList
+        reservations={rows}
+        showBerth
+        emptyMessage="This client has no active reservations."
+      />
+    </div>
+  );
+}