[Nav] Add ثبت آگهی CTA, streamline menu, active-link highlight, role dashboards

Header gets a prominent accent ＋ثبت آگهی CTA → /Employer/Index (auth redirect handles login → register/post). Main nav trimmed to the 5 core public links (خانه/شیفت‌ها/استخدام/مراکز/تقویم); دریافت اپ + راهنما live in the footer and علاقه‌مندی‌ها in the profile menu, so the bar is far less crowded. Added active-page highlight (accent underline on desktop, soft background on mobile). Login now sends admins to /Admin/Overview (dashboard) instead of the ingestion queue; employers→/Employer/Index, job-seekers→/Me already in place.

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

src/JobsMedical.Web/Pages/Account/Login.cshtml.cs

@@ -106,7 +106,7 @@ public class LoginModel : PageModel
         // Route to the right panel for the account type.
         return user.Role switch
         {
-            UserRole.Admin => RedirectToPage("/Admin/Index"),
+            UserRole.Admin => RedirectToPage("/Admin/Overview"),
             UserRole.FacilityAdmin => RedirectToPage("/Employer/Index"),
             _ => RedirectToPage("/Me/Index"),
         };