Add «آماده به کار» (talent) listing type — workers offering themselves

Adds a third listing kind alongside Shift/Job for healthcare staff who
advertise their own availability (very common in Iranian medical
channels, e.g. "دندانپزشک آماده همکاری… ۵۰٪ تسویه"). These have no
facility; the contact phone is the key field.

- Model: TalentListing (role, person name, years, licensed, city/district,
  area note, availability, gender, comp, phone) + ListingKind.Talent +
  RawListing.LinkedTalentId + DbSet/relations/indexes + EF migration.
- Parser: detect آماده‌به‌کار/جویای کار → Kind=Talent; extract person name,
  years of experience, licensed flag, area («منطقه ۱»), phone. Facility
  name extraction now skipped for talent.
- Validator: talent path scores role + phone + medical (no facility/pay
  required).
- Ingestion auto-publish: creates a TalentListing for talent kind.
- Review (manual publish): Talent option + talent fields; publishes a
  TalentListing without a facility. Shift/Job facility now falls back to a
  shared «نامشخص / ثبت نشده» record when the ad names none — publishing
  never fails on a missing facility.
- Browse /Talent (indexable, filters: city/district/role/gender),
  details /Talent/Details (noindex — personal contact, tel: call button),
  _TalentCard, badge-talent, nav link, home section.
- Sitemap includes /Talent; robots disallows /Talent/Details. Archiver
  expires stale talent listings.

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

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

@@ -113,6 +113,7 @@
                     <a asp-page="/Index" class="@(path == "/" ? "active" : null)">خانه</a>
                     <a asp-page="/Shifts/Index" data-tour="shifts" class="@(path.StartsWith("/Shifts") ? "active" : null)">شیفت‌ها</a>
                     <a asp-page="/Jobs/Index" 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>
                     <a asp-page="/Facilities/Index" class="@(path.StartsWith("/Facilities") ? "active" : null)">مراکز درمانی</a>
                     <a asp-page="/Calendar/Index" class="@(path.StartsWith("/Calendar") ? "active" : null)">تقویم هفتگی</a>
                 </nav>