Facility location: click-to-pick Neshan map + 'my current location'

- RegisterFacility: '📍 موقعیت فعلی من' (browser geolocation, always available) + Neshan Leaflet map (click/drag marker → fills lat/lng) when a Neshan web key is set; graceful fallback to manual coords without a key
- AppSetting.NeshanMapKey configured in /Admin/Settings (Google Maps is blocked in Iran); migration
- Verified: location button + inputs render always; map + SDK render once the key is saved

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

src/JobsMedical.Web/Pages/Admin/Settings.cshtml.cs

@@ -36,6 +36,7 @@ public class SettingsModel : PageModel
     [BindProperty] public string? SmsApiKey { get; set; }
     [BindProperty] public string? SmsTemplate { get; set; }
     [BindProperty] public string? SmsSender { get; set; }
+    [BindProperty] public string? NeshanMapKey { get; set; }
     [TempData] public string? Saved { get; set; }
 
     public async Task OnGetAsync()
@@ -64,6 +65,7 @@ public class SettingsModel : PageModel
         SmsApiKey = s.SmsApiKey;
         SmsTemplate = s.SmsTemplate;
         SmsSender = s.SmsSender;
+        NeshanMapKey = s.NeshanMapKey;
     }
 
     public async Task<IActionResult> OnPostAsync()
@@ -93,6 +95,7 @@ public class SettingsModel : PageModel
             SmsApiKey = SmsApiKey,
             SmsTemplate = SmsTemplate,
             SmsSender = SmsSender,
+            NeshanMapKey = NeshanMapKey,
         });
         Saved = "تنظیمات ذخیره شد.";
         return RedirectToPage();