[Alerts] Customizable job alerts + Help capabilities showcase

Job alerts (هشدار شغلی): users save what they want — scope (shift/job/both), role, city, shift type, employment type, minimum pay — and get notified when an employer posts a match. New JobAlert model + AlertScope enum + DbContext (user-cascade, role set-null, IsActive index) + migration. /Me/Alerts page to create/pause/delete alerts; entry point added to the کارجو panel. NotificationService.NotifyNewShift/Job now unions preference matches with active-alert matches (deduped) so alert owners are notified on publish. Help page gains an 'امکانات همکادر' capability showcase grid (with a 'ساخت هشدار شغلی' CTA) so the page demonstrates what the app does.

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

src/JobsMedical.Web/Services/NotificationService.cs

@@ -45,7 +45,9 @@ public class NotificationService
             .FirstOrDefaultAsync(x => x.Id == shiftId);
         if (s is null) return;
 
-        var users = await MatchingUserIdsAsync(s.RoleId, s.Facility.CityId, s.ShiftType);
+        var prefUsers = await MatchingUserIdsAsync(s.RoleId, s.Facility.CityId, s.ShiftType);
+        var alertUsers = await ShiftAlertUserIdsAsync(s);
+        var users = prefUsers.Union(alertUsers).Distinct().ToList();
         var title = $"شیفت جدید: {s.Role.Name}";
         var body = $"{s.Facility.Name} — {JalaliDate.WeekDayName(s.Date)} {JalaliDate.Time(s.StartTime)}";
         await AddAsync(users, title, body, $"/Shifts/Details/{s.Id}");
@@ -57,7 +59,9 @@ public class NotificationService
             .FirstOrDefaultAsync(x => x.Id == jobId);
         if (j is null) return;
 
-        var users = await MatchingUserIdsAsync(j.RoleId, j.Facility.CityId, null);
+        var prefUsers = await MatchingUserIdsAsync(j.RoleId, j.Facility.CityId, null);
+        var alertUsers = await JobAlertUserIdsAsync(j);
+        var users = prefUsers.Union(alertUsers).Distinct().ToList();
         await AddAsync(users, $"استخدام جدید: {j.Title}", j.Facility.Name, $"/Jobs/Details/{j.Id}");
     }
 
@@ -75,6 +79,36 @@ public class NotificationService
         return await q.Distinct().ToListAsync();
     }
 
+    /// <summary>Owners of active job alerts that match this shift.</summary>
+    private async Task<List<int>> ShiftAlertUserIdsAsync(Shift s)
+    {
+        var cityId = s.Facility.CityId;
+        var districtId = s.Facility.DistrictId;
+        return await _db.JobAlerts.Where(a => a.IsActive
+                && a.Scope != AlertScope.Jobs
+                && (a.RoleId == null || a.RoleId == s.RoleId)
+                && (a.CityId == null || a.CityId == cityId)
+                && (a.DistrictId == null || a.DistrictId == districtId)
+                && (a.ShiftType == null || a.ShiftType == s.ShiftType)
+                && (a.MinPay == null || (s.PayAmount != null && s.PayAmount >= a.MinPay)))
+            .Select(a => a.UserId).Distinct().ToListAsync();
+    }
+
+    /// <summary>Owners of active job alerts that match this hiring opening.</summary>
+    private async Task<List<int>> JobAlertUserIdsAsync(JobOpening j)
+    {
+        var cityId = j.Facility.CityId;
+        var districtId = j.Facility.DistrictId;
+        return await _db.JobAlerts.Where(a => a.IsActive
+                && a.Scope != AlertScope.Shifts
+                && (a.RoleId == null || a.RoleId == j.RoleId)
+                && (a.CityId == null || a.CityId == cityId)
+                && (a.DistrictId == null || a.DistrictId == districtId)
+                && (a.EmploymentType == null || a.EmploymentType == j.EmploymentType)
+                && (a.MinPay == null || ((j.SalaryMax ?? j.SalaryMin) != null && (j.SalaryMax ?? j.SalaryMin) >= a.MinPay)))
+            .Select(a => a.UserId).Distinct().ToListAsync();
+    }
+
     private async Task AddAsync(List<int> userIds, string title, string? body, string url)
     {
         if (userIds.Count == 0) return;