Add per-user Like (پسندیدن) with a liked page and counts

Logged-in users can like a listing (job/shift/talent); dislike is removed per request — only likes.
- Like model (polymorphic by TargetType+TargetId) + EF migration; unique per (user, listing).
- POST /like toggles the like (auth required) and returns {liked, count}.
- Detail pages: the old ♡ Save / ✕ Dismiss buttons are replaced by a single heart Like button that
  shows the live count and toggles in place; clicking while logged out redirects to login.
- New «❤️ پسندیده‌ها» page (/Me/Liked) lists everything the user liked (open listings only), with a
  nav entry shown only when authenticated.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/JobsMedical.Web/Pages/Shared/_Layout.cshtml

@@ -112,6 +112,10 @@
                 <nav class="main-nav">
                     <a asp-page="/Index" class="@(path == "/" ? "active" : null)">خانه</a>
                     <a asp-page="/Recommendations/Index" class="@(path.StartsWith("/Recommendations") ? "active" : null)">✨ پیشنهادها</a>
+                    @if (User.Identity?.IsAuthenticated == true)
+                    {
+                        <a asp-page="/Me/Liked" class="@(path.StartsWith("/Me/Liked") ? "active" : null)">❤️ پسندیده‌ها</a>
+                    }
                     <a href="/Shifts" data-tour="shifts" class="@(path.StartsWith("/Shifts") ? "active" : null)">شیفت‌ها</a>
                     <a href="/Jobs" data-tour="jobs" class="@(path.StartsWith("/Jobs") ? "active" : null)">استخدام</a>
                     <a asp-page="/Talent/Index" class="@(path.StartsWith("/Talent") ? "active" : null)">آماده به کار</a>
@@ -290,6 +294,36 @@
             <div id="contactModalBody" class="contact-modal-body"></div>
         </div>
     </div>
+    @* Like («پسندیدن») toggle — login-gated, updates the button state + count in place. *@
+    <script>
+    (function () {
+        function fa(n) { return String(n).replace(/[0-9]/g, function (d) { return '۰۱۲۳۴۵۶۷۸۹'[+d]; }); }
+        document.addEventListener('click', function (e) {
+            var b = e.target.closest('.like-trigger');
+            if (!b) return;
+            e.preventDefault();
+            if (document.body.dataset.authed !== '1') {
+                location.href = '/Account/Login?returnUrl=' + encodeURIComponent(location.pathname);
+                return;
+            }
+            var fd = new FormData();
+            fd.append('type', b.dataset.likeType);
+            fd.append('id', b.dataset.likeId);
+            b.disabled = true;
+            fetch('/like', { method: 'POST', body: fd })
+                .then(function (r) { return r.ok ? r.json() : Promise.reject(); })
+                .then(function (d) {
+                    b.dataset.liked = d.liked ? 'true' : 'false';
+                    b.classList.toggle('btn-accent', d.liked);
+                    b.classList.toggle('btn-outline', !d.liked);
+                    var ico = b.querySelector('.like-ico'); if (ico) ico.textContent = d.liked ? '♥' : '♡';
+                    var c = b.querySelector('.like-count'); if (c) c.textContent = fa(d.count);
+                })
+                .catch(function () {})
+                .finally(function () { b.disabled = false; });
+        });
+    })();
+    </script>
     <script>
     (function () {
         var modal = document.getElementById('contactModal');