feat: Add customer management, payments, and push notifications with security enhancements

Major Feature Additions:
- Customer management: Full CRUD with data export and privacy compliance
- Payment management: Centralized payment tracking and administration
- Push notification subscriptions: Manage and track web push subscriptions

Security Enhancements:
- IP whitelist middleware for administrative endpoints
- Data retention service with configurable policies
- Enhanced push notification security documentation
- Security fixes progress tracking (2025-11-14)

UI/UX Improvements:
- Enhanced navigation with improved mobile responsiveness
- Updated admin dashboard with order status counts
- Improved product CRUD forms
- New customer and payment management interfaces

Backend Improvements:
- Extended customer service with data export capabilities
- Enhanced order service with status count queries
- Improved crypto payment service with better error handling
- Updated validators and configuration

Documentation:
- DEPLOYMENT_NGINX_GUIDE.md: Nginx deployment instructions
- IP_STORAGE_ANALYSIS.md: IP storage security analysis
- PUSH_NOTIFICATION_SECURITY.md: Push notification security guide
- UI_UX_IMPROVEMENT_PLAN.md: Planned UI/UX enhancements
- UI_UX_IMPROVEMENTS_COMPLETED.md: Completed improvements

Cleanup:
- Removed temporary database WAL files
- Removed stale commit message file

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

LittleShop/Areas/Admin/Controllers/PushSubscriptionsController.cs

@@ -0,0 +1,107 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using LittleShop.Services;
+
+namespace LittleShop.Areas.Admin.Controllers;
+
+[Area("Admin")]
+[Authorize(AuthenticationSchemes = "Cookies", Roles = "Admin")]
+public class PushSubscriptionsController : Controller
+{
+    private readonly IPushNotificationService _pushService;
+    private readonly ILogger<PushSubscriptionsController> _logger;
+
+    public PushSubscriptionsController(
+        IPushNotificationService pushService,
+        ILogger<PushSubscriptionsController> logger)
+    {
+        _pushService = pushService;
+        _logger = logger;
+    }
+
+    // GET: Admin/PushSubscriptions
+    public async Task<IActionResult> Index()
+    {
+        try
+        {
+            var subscriptions = await _pushService.GetActiveSubscriptionsAsync();
+            return View(subscriptions.OrderByDescending(s => s.SubscribedAt));
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Error retrieving push subscriptions list");
+            TempData["ErrorMessage"] = "Failed to load push subscriptions. Please try again.";
+            return View(new List<LittleShop.Models.PushSubscription>());
+        }
+    }
+
+    // POST: Admin/PushSubscriptions/Delete/{id}
+    [HttpPost]
+    [ValidateAntiForgeryToken]
+    public async Task<IActionResult> Delete(int id)
+    {
+        try
+        {
+            // Find subscription by ID and delete via UnsubscribeAsync (which uses endpoint)
+            var subscriptions = await _pushService.GetActiveSubscriptionsAsync();
+            var subscription = subscriptions.FirstOrDefault(s => s.Id == id);
+
+            if (subscription == null)
+            {
+                TempData["ErrorMessage"] = "Push subscription not found.";
+                return RedirectToAction(nameof(Index));
+            }
+
+            var success = await _pushService.UnsubscribeAsync(subscription.Endpoint);
+
+            if (success)
+            {
+                _logger.LogInformation("Deleted push subscription {Id} (Endpoint: {Endpoint})", id, subscription.Endpoint);
+                TempData["SuccessMessage"] = "Push subscription deleted successfully.";
+            }
+            else
+            {
+                _logger.LogWarning("Failed to delete push subscription {Id}", id);
+                TempData["ErrorMessage"] = "Failed to delete push subscription.";
+            }
+
+            return RedirectToAction(nameof(Index));
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Error deleting push subscription {Id}", id);
+            TempData["ErrorMessage"] = $"Error deleting push subscription: {ex.Message}";
+            return RedirectToAction(nameof(Index));
+        }
+    }
+
+    // POST: Admin/PushSubscriptions/CleanupExpired
+    [HttpPost]
+    [ValidateAntiForgeryToken]
+    public async Task<IActionResult> CleanupExpired()
+    {
+        try
+        {
+            var deletedCount = await _pushService.CleanupExpiredSubscriptionsAsync();
+
+            _logger.LogInformation("Cleaned up {Count} expired push subscriptions", deletedCount);
+
+            if (deletedCount > 0)
+            {
+                TempData["SuccessMessage"] = $"Successfully cleaned up {deletedCount} expired subscription(s).";
+            }
+            else
+            {
+                TempData["InfoMessage"] = "No expired subscriptions found to clean up.";
+            }
+
+            return RedirectToAction(nameof(Index));
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Error cleaning up expired push subscriptions");
+            TempData["ErrorMessage"] = $"Error during cleanup: {ex.Message}";
+            return RedirectToAction(nameof(Index));
+        }
+    }
+}