feat(items): show Cheapest and Closest tags independent of sort order

Previously tags were tied to the active sort (only Closest showed when
sorting by distance, only Cheapest when sorting by price). Now both are
computed independently — Cheapest = vendor with min price, Closest =
vendor with min distanceKm — and shown simultaneously when a site is
selected, regardless of which sort is active.

Verified with Playwright: both tags present under distance sort, price
sort, and absent when no site is selected.

App/pelagia-portal/app/(portal)/inventory/items/items-table.tsx

@@ -193,6 +193,12 @@ export function ItemsTable({
               const lowestPrice = item.vendors.length > 0 ? Math.min(...item.vendors.map((v) => v.price)) : null;
               const sortedVendors = getSortedVendors(item.vendors);
 
+              // Cheapest and closest are independent of current sort order
+              const minPrice = sortedVendors.length > 1 ? Math.min(...sortedVendors.map((v) => v.price)) : null;
+              const closestVendorId = hasSite
+                ? (sortedVendors.filter((v) => v.distanceKm !== null).sort((a, b) => a.distanceKm! - b.distanceKm!)[0]?.vendorId ?? null)
+                : null;
+
               return (
                 <Fragment key={item.id}>
                   {/* Item row */}
@@ -239,9 +245,10 @@ export function ItemsTable({
                               </tr>
                             </thead>
                             <tbody className="divide-y divide-neutral-100">
-                              {sortedVendors.map((vendor, idx) => {
+                              {sortedVendors.map((vendor) => {
                                 const key = `${item.id}-${vendor.vendorId}`;
-                                const isFirst = idx === 0;
+                                const isCheapest = minPrice !== null && vendor.price === minPrice;
+                                const isClosest = closestVendorId !== null && vendor.vendorId === closestVendorId;
                                 return (
                                   <tr key={vendor.vendorId} className="hover:bg-white">
                                     <td className="px-12 py-2.5">
@@ -256,10 +263,10 @@ export function ItemsTable({
                                         {vendor.isVerified && (
                                           <span className="rounded-full bg-success-100 px-1.5 py-0.5 text-xs font-medium text-success-700">Verified</span>
                                         )}
-                                        {isFirst && sortBy === "distance" && vendor.distanceKm !== null && (
+                                        {isClosest && (
                                           <span className="text-xs text-primary-600 font-medium">★ Closest</span>
                                         )}
-                                        {isFirst && sortBy === "price" && (
+                                        {isCheapest && (
                                           <span className="text-xs text-success-600 font-medium">Cheapest</span>
                                         )}
                                       </div>