a11y: make tender card date keyboard accessible

src/components/TenderCard.jsx

@@ -32,9 +32,10 @@ export const TenderCard = ({ tender }) => {
     <div className="bg-white rounded-xl border border-blue-200/80 shadow-xs hover:shadow-md transition-all overflow-hidden flex flex-col md:flex-row group border-l-4 border-l-blue-600">
       
       {/* Left Date Block */}
-      <div 
+      <button type="button"
         onClick={() => setActiveTenderDetail(tender)}
-        className="bg-[#edf4ff] group-hover:bg-[#e2edff] text-blue-900 md:w-36 p-4 flex flex-col items-center justify-center shrink-0 border-b md:border-b-0 md:border-r border-blue-100 cursor-pointer select-none transition-colors"
+        aria-label={`${tender.tarih || 'Tarih doğrulanmalı'} tarih bilgisi; ihale detayını aç`}
+        className="bg-[#edf4ff] group-hover:bg-[#e2edff] text-blue-900 md:w-36 p-4 flex flex-col items-center justify-center shrink-0 border-b md:border-b-0 md:border-r border-blue-100 cursor-pointer select-none transition-colors text-center focus-visible:outline-2 focus-visible:outline-blue-600 focus-visible:outline-offset-[-2px]"
       >
         <span className="text-[9px] font-black uppercase tracking-widest text-blue-900/50">İhale</span>
         <span className="text-3xl font-black tracking-tight text-blue-700 leading-none">{day}</span>
@@ -42,7 +43,7 @@ export const TenderCard = ({ tender }) => {
         <span className="text-[11px] font-semibold bg-white/80 px-2 py-0.5 rounded-full text-blue-800 mt-2 border border-blue-200">
           {tender.saat || 'Saat doğrulanmalı'}
         </span>
-      </div>
+      </button>
 
       {/* Main Card Content */}
       <div className="flex-1 p-4 flex flex-col justify-between space-y-3">