Add iranestekhdam.ir as an ingestion source (clinical job ads at named facilities)

New IranEstekhdamListingSource: reads the site monthly ad sitemaps
(sitemap-ads.xml -> sitemap-ads-YYYY-M.xml), keeps only ad URLs whose Persian slug names a
clinical role (veterinary/non-clinical excluded), then extracts each ad title + description
(+ phone). These are employer ads at NAMED facilities, so they directly improve the
unknown-facility problem the classifieds content has.

Wired in like Medjobs: AppSetting toggles (IranEstekhdamEnabled/MaxAds/UseProxy) + EF
migration, SettingsService persistence, admin Settings UI, and DI registration. Off by
default; the medical-gate validator + AI auditor + junk filters screen results downstream.

Note: e-estekhdam / jobinja / jobvision are JS-rendered SPAs whose ad lists are not in static
HTML, so they need API reverse-engineering (a separate effort), not this static-scrape path.

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

src/JobsMedical.Web/Models/AppSetting.cs

@@ -81,6 +81,12 @@ public class AppSetting
     /// <summary>Max ads to fetch per ingestion run (be polite; dedupe skips already-seen).</summary>
     public int MedjobsMaxAds { get; set; } = 40;
 
+    /// <summary>Scrape iranestekhdam.ir clinical job ads (crawled via its monthly ad sitemaps;
+    /// employer ads at named facilities, filtered to clinical-role slugs).</summary>
+    public bool IranEstekhdamEnabled { get; set; } = false;
+    public int IranEstekhdamMaxAds { get; set; } = 40;
+    public bool IranEstekhdamUseProxy { get; set; } = false;
+
     // --- SMS OTP (Kavenegar). When off, the code is shown on screen (dev only). ---
     public bool SmsEnabled { get; set; } = false;
     [MaxLength(200)] public string? SmsApiKey { get; set; }