feat: add other-DB delete, expand import, bump v1.1.0

- Add DatabasePreviewService.DeleteDatabaseFileAsync with active-DB
  safety guard; refactor DeleteBackup to use it
- Add Delete button and handler for Previous Database Versions Found
  files in Database Settings
- Expand import to cover 7 additional tables: CalendarEvents,
  Inspections, Checklists, ChecklistItems, SecurityDeposits, Notes,
  Notifications - with required-cols sets and ImportResult DTO properties
- Add preview DTOs, count cards, tabs, and data panels for all 7 tables
  in DatabasePreview.razor
- ImportNotificationsAsync: fan out each notification to all real users
  (excluding system user) with fresh IDs
- Fix SignalR ObjectDisposedException in NotificationCenter on dispose
- Bump application and database version to 1.1.0

Author: CIS Guru

2-Nine.Application/Models/DTOs/DatabasePreviewDTOs.cs

@@ -13,6 +13,13 @@ public class DatabasePreviewData
     public int MaintenanceCount { get; set; }
     public int RepairCount { get; set; }
     public int DocumentCount { get; set; }
+    public int CalendarEventCount { get; set; }
+    public int InspectionCount { get; set; }
+    public int ChecklistCount { get; set; }
+    public int ChecklistItemCount { get; set; }
+    public int SecurityDepositCount { get; set; }
+    public int NoteCount { get; set; }
+    public int NotificationCount { get; set; }
 
     public List<PropertyPreview> Properties { get; set; } = new();
     public List<TenantPreview> Tenants { get; set; } = new();
@@ -21,6 +28,13 @@ public class DatabasePreviewData
     public List<PaymentPreview> Payments { get; set; } = new();
     public List<MaintenancePreview> MaintenanceRequests { get; set; } = new();
     public List<RepairPreview> Repairs { get; set; } = new();
+    public List<CalendarEventPreview> CalendarEvents { get; set; } = new();
+    public List<InspectionPreview> Inspections { get; set; } = new();
+    public List<ChecklistPreview> Checklists { get; set; } = new();
+    public List<ChecklistItemPreview> ChecklistItems { get; set; } = new();
+    public List<SecurityDepositPreview> SecurityDeposits { get; set; } = new();
+    public List<NotePreview> Notes { get; set; } = new();
+    public List<NotificationPreview> Notifications { get; set; } = new();
 }
 
 /// <summary>
@@ -121,6 +135,88 @@ public class RepairPreview
     public decimal Cost { get; set; }
 }
 
+/// <summary>
+/// DTO for calendar event preview in read-only database view
+/// </summary>
+public class CalendarEventPreview
+{
+    public Guid Id { get; set; }
+    public string Title { get; set; } = string.Empty;
+    public DateTime StartOn { get; set; }
+    public string EventType { get; set; } = string.Empty;
+    public string Status { get; set; } = string.Empty;
+}
+
+/// <summary>
+/// DTO for inspection preview in read-only database view
+/// </summary>
+public class InspectionPreview
+{
+    public Guid Id { get; set; }
+    public string PropertyAddress { get; set; } = string.Empty;
+    public DateTime CompletedOn { get; set; }
+    public string InspectionType { get; set; } = string.Empty;
+    public string? InspectedBy { get; set; }
+}
+
+/// <summary>
+/// DTO for checklist preview in read-only database view
+/// </summary>
+public class ChecklistPreview
+{
+    public Guid Id { get; set; }
+    public string Name { get; set; } = string.Empty;
+    public string ChecklistType { get; set; } = string.Empty;
+    public string Status { get; set; } = string.Empty;
+}
+
+/// <summary>
+/// DTO for checklist item preview in read-only database view
+/// </summary>
+public class ChecklistItemPreview
+{
+    public Guid Id { get; set; }
+    public Guid ChecklistId { get; set; }
+    public string ItemText { get; set; } = string.Empty;
+    public int ItemOrder { get; set; }
+}
+
+/// <summary>
+/// DTO for security deposit preview in read-only database view
+/// </summary>
+public class SecurityDepositPreview
+{
+    public Guid Id { get; set; }
+    public string TenantName { get; set; } = string.Empty;
+    public decimal Amount { get; set; }
+    public DateTime DateReceived { get; set; }
+    public string PaymentMethod { get; set; } = string.Empty;
+    public string Status { get; set; } = string.Empty;
+}
+
+/// <summary>
+/// DTO for note preview in read-only database view
+/// </summary>
+public class NotePreview
+{
+    public Guid Id { get; set; }
+    public string EntityType { get; set; } = string.Empty;
+    public string Content { get; set; } = string.Empty;
+    public DateTime? CreatedOn { get; set; }
+}
+
+/// <summary>
+/// DTO for notification preview in read-only database view
+/// </summary>
+public class NotificationPreview
+{
+    public Guid Id { get; set; }
+    public string Title { get; set; } = string.Empty;
+    public string Type { get; set; } = string.Empty;
+    public string Category { get; set; } = string.Empty;
+    public DateTime SentOn { get; set; }
+}
+
 /// <summary>
 /// Represents a non-backup database file found in the data directory (e.g. an older versioned DB)
 /// </summary>
@@ -155,10 +251,19 @@ public class ImportResult
     public int MaintenanceRequestsImported { get; set; }
     public int RepairsImported { get; set; }
     public int DocumentsImported { get; set; }
+    public int CalendarEventsImported { get; set; }
+    public int InspectionsImported { get; set; }
+    public int ChecklistsImported { get; set; }
+    public int ChecklistItemsImported { get; set; }
+    public int SecurityDepositsImported { get; set; }
+    public int NotesImported { get; set; }
+    public int NotificationsImported { get; set; }
     public List<string> Errors { get; set; } = new();
 
     public int TotalImported => PropertiesImported + TenantsImported + LeasesImported
-        + InvoicesImported + PaymentsImported + MaintenanceRequestsImported + RepairsImported + DocumentsImported;
+        + InvoicesImported + PaymentsImported + MaintenanceRequestsImported + RepairsImported + DocumentsImported
+        + CalendarEventsImported + InspectionsImported + ChecklistsImported + ChecklistItemsImported
+        + SecurityDepositsImported + NotesImported + NotificationsImported;
 }
 
 /// <summary>