Add medjobs.ir scraper + employer/employee choice at signup

- MedjobsListingSource: crawls medjobs.ir sitemaps (ad_listing-sitemapN) → fetches ad pages → title+description → engine (dedupe/parse/validate/publish as SEO job pages). Configured in /Admin/Settings (enable + max ads/run).
- Login/register now asks 'کادر درمان' vs 'کارفرما/مرکز': new accounts get Doctor vs FacilityAdmin role; post-login routes to /Me, /Employer, or /Admin accordingly.
- Verified live: medjobs run fetched real ads into the review queue; employer signup → /Employer.

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

src/JobsMedical.Web/Migrations/AppDbContextModelSnapshot.cs

@@ -80,6 +80,12 @@ namespace JobsMedical.Web.Migrations
                     b.Property<int>("IngestIntervalMinutes")
                         .HasColumnType("integer");
 
+                    b.Property<bool>("MedjobsEnabled")
+                        .HasColumnType("boolean");
+
+                    b.Property<int>("MedjobsMaxAds")
+                        .HasColumnType("integer");
+
                     b.Property<int>("Mode")
                         .HasColumnType("integer");