feat(companies): show member + yacht counts on list page

listCompanies returns memberCount (active companyMemberships)
and yachtCount (yachts where currentOwnerType=company), each
fetched as a parallel grouped count after the main page query.
Two new badge columns in company-columns render them between
the tax-id and status columns.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/companies/company-columns.tsx

@@ -4,6 +4,7 @@ import Link from 'next/link';
 import { MoreHorizontal, Pencil, Archive, Eye } from 'lucide-react';
 import type { ColumnDef } from '@tanstack/react-table';
 
+import { Badge } from '@/components/ui/badge';
 import { Button } from '@/components/ui/button';
 import {
   DropdownMenu,
@@ -12,7 +13,6 @@ import {
   DropdownMenuTrigger,
 } from '@/components/ui/dropdown-menu';
 
-// TODO: add member/yacht counts once the list endpoint returns them via a join.
 export interface CompanyRow {
   id: string;
   name: string;
@@ -27,6 +27,8 @@ export interface CompanyRow {
   archivedAt: string | null;
   createdAt: string;
   updatedAt: string;
+  memberCount?: number;
+  yachtCount?: number;
 }
 
 const STATUS_COLORS: Record<string, string> = {
@@ -88,6 +90,28 @@ export function getCompanyColumns({
         return <span className="text-sm">{value}</span>;
       },
     },
+    {
+      id: 'memberCount',
+      header: 'Members',
+      enableSorting: false,
+      size: 88,
+      cell: ({ row }) => {
+        const n = row.original.memberCount ?? 0;
+        if (n === 0) return <span className="text-muted-foreground">—</span>;
+        return <Badge variant="secondary">{n}</Badge>;
+      },
+    },
+    {
+      id: 'yachtCount',
+      header: 'Yachts',
+      enableSorting: false,
+      size: 88,
+      cell: ({ row }) => {
+        const n = row.original.yachtCount ?? 0;
+        if (n === 0) return <span className="text-muted-foreground">—</span>;
+        return <Badge variant="secondary">{n}</Badge>;
+      },
+    },
     {
       id: 'status',
       accessorKey: 'status',