Fix responsive UI: mobile nav, fluid typography, pay-label & calendar overflow

- Mobile nav was display:none (no navigation on phones) → now a scrollable strip on a second header row
- Fluid typography via clamp() for hero/page/section headings + spacing
- Long pay/choice labels (… یا … به انتخاب شما) now wrap in card footers instead of overflowing
- Calendar table scrolls horizontally on small screens (cal-wrap + min-width)
- Filter sidebar non-sticky/full-width on mobile; tighter small-screen padding & buttons

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

src/JobsMedical.Web/Pages/Calendar/Index.cshtml

@@ -34,6 +34,7 @@
            asp-route-FacilityId="@Model.FacilityId" asp-route-WeekOffset="@(Model.WeekOffset + 1)">هفته بعد ←</a>
     </div>
 
+    <div class="cal-wrap">
     <table class="cal">
         <thead>
             <tr>
@@ -69,4 +70,5 @@
             </tr>
         </tbody>
     </table>
+    </div>
 </div>