[Notify] Notify the employer when someone applies to their listing

Applications were recorded but the facility owner was never pinged. NotificationService gains NotifyShiftApplicationAsync/NotifyJobApplicationAsync (look up the facility owner, notify via in-app bell + live SSE + push, linking to /Employer/Listings). InterestService fires them when a NEW Apply event is saved (after the duplicate guard, so no repeat pings; View/Save/Dismiss don't notify). No-op for admin-managed facilities with no owner.

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

src/JobsMedical.Web/Services/InterestService.cs

@@ -12,11 +12,13 @@ public class InterestService
 {
     private readonly AppDbContext _db;
     private readonly VisitorContext _visitor;
+    private readonly NotificationService _notify;
 
-    public InterestService(AppDbContext db, VisitorContext visitor)
+    public InterestService(AppDbContext db, VisitorContext visitor, NotificationService notify)
     {
         _db = db;
         _visitor = visitor;
+        _notify = notify;
     }
 
     public string VisitorId => _visitor.VisitorId;
@@ -53,6 +55,7 @@ public class InterestService
             EventType = type,
         });
         await _db.SaveChangesAsync();
+        if (type == InterestEventType.Apply) await _notify.NotifyShiftApplicationAsync(shiftId);   // ping the employer
     }
 
     public async Task LogJobAsync(InterestEventType type, int jobOpeningId)
@@ -69,6 +72,7 @@ public class InterestService
             EventType = type,
         });
         await _db.SaveChangesAsync();
+        if (type == InterestEventType.Apply) await _notify.NotifyJobApplicationAsync(jobOpeningId);   // ping the employer
     }
 
     public Task<UserPreferences?> GetPreferencesAsync()

src/JobsMedical.Web/Services/NotificationService.cs

@@ -65,6 +65,27 @@ public class NotificationService
         await AddAsync(users, $"استخدام جدید: {j.Title}", j.Facility.Name, $"/Jobs/Details/{j.Id}");
     }
 
+    /// <summary>Notify the facility owner that someone declared interest in their shift.</summary>
+    public async Task NotifyShiftApplicationAsync(int shiftId)
+    {
+        var s = await _db.Shifts.Include(x => x.Facility).Include(x => x.Role)
+            .FirstOrDefaultAsync(x => x.Id == shiftId);
+        if (s?.Facility?.OwnerUserId is not int owner) return;   // admin-managed facility → no owner to notify
+        var body = $"{s.Facility.Name} — {JalaliDate.WeekDayName(s.Date)} {JalaliDate.Time(s.StartTime)}";
+        await AddAsync(new List<int> { owner }, $"متقاضی جدید برای شیفت {s.Role?.Name}", body,
+            $"/Employer/Listings?facilityId={s.FacilityId}");
+    }
+
+    /// <summary>Notify the facility owner that someone declared interest in their hiring opening.</summary>
+    public async Task NotifyJobApplicationAsync(int jobId)
+    {
+        var j = await _db.JobOpenings.Include(x => x.Facility)
+            .FirstOrDefaultAsync(x => x.Id == jobId);
+        if (j?.Facility?.OwnerUserId is not int owner) return;
+        await AddAsync(new List<int> { owner }, $"متقاضی جدید: {j.Title}", j.Facility.Name,
+            $"/Employer/Listings?facilityId={j.FacilityId}");
+    }
+
     /// <summary>Users with a non-empty preference that matches the listing (via their visitor link).</summary>
     private async Task<List<int>> MatchingUserIdsAsync(int roleId, int cityId, ShiftType? shiftType)
     {