Search: Elasticsearch-style highlighted match snippets (results + typeahead)

- SearchHighlight.Snippet: extracts a ±70-char window around the first
  matching term and marks it (with ellipses) — the ES "highlight" fragment.
- Result cards (shift/job/talent) now show that snippet from the matched
  description/tags when a query is present, so you SEE where the term hit
  (e.g. «…دارای مدرک <mark>mmt</mark>…») instead of just the role.
- Typeahead suggestions gain a highlighted "sub" line (talent→tags,
  shift→city·specialty, job→facility·city) so matches show in the dropdown too.

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

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

@@ -35,6 +35,11 @@
     }
     <div class="row">📅 @JalaliDate.WeekDayName(Model.Date)، @JalaliDate.ToLongDate(Model.Date)</div>
     <div class="row">🕐 @JalaliDate.Time(Model.StartTime) تا @JalaliDate.Time(Model.EndTime)</div>
+    @{ var snip = JobsMedical.Web.Services.SearchHighlight.Snippet(Model.Description, q); }
+    @if (snip.Value.Length > 0)
+    {
+        <div class="search-snippet">@snip</div>
+    }
     <partial name="_HourBar" model="Model" />
     <div class="foot">
         <span class="pay">@JalaliDate.PayLabel(Model.PayType, Model.PayAmount, Model.SharePercent)</span>