feat: Add ProfileWork with Hangfire job synchronization

- ProfileWork.cs: Business logic for DB-to-Hangfire sync
- Fetches active profiles from database via MediatR
- Registers/updates Hangfire recurring jobs with local timezone
- Removes stale jobs (deleted from DB)
- O(n) performance optimization using HashSet for lookups
- Uses ProfileWorker's stopping token for graceful shutdown

Job lifecycle:
- ProfileWorker stops → All running jobs cancelled via token closure
- Jobs use RecurringJobOptions with TimeZoneInfo.Local
- Automatic retry support via Hangfire [AutomaticRetry] attribute

ECMJobRunner.WebCron/ProfileWorker/ProfileWork.cs

@@ -0,0 +1,60 @@
+using ECMJobRunner.Application.DEXJob.Queries;
+using ECMJobRunner.WebCron.Extensions;
+using Hangfire;
+using MediatR;
+
+namespace ECMJobRunner.WebCron.ProfileWorker;
+
+
+public class ProfileWork(ILogger<ProfileWork> Logger, IRecurringJobManager JobManager, IMediator Mediator, ProfileCache ProfileCache)
+{
+    public async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        // Fetch active profiles from database
+        var profiles = await Mediator.Send(new GetProfileQuery()
+        {
+            Active = true,
+            IncludeSqlJobs = true
+        }, stoppingToken);
+
+        // Create HashSet for O(1) lookup performance
+        var profileJobIds = profiles.Select(p => p.JobId()).ToHashSet();
+
+        // Remove jobs from Hangfire that no longer exist in the database
+        foreach (var cachedJobId in ProfileCache.GetAllJobIds())
+        {
+            if (!profileJobIds.Contains(cachedJobId))
+            {
+                // Remove job from Hangfire if it no longer exists in the database
+                JobManager.RemoveIfExists(cachedJobId);
+                ProfileCache.TryRemove(cachedJobId, out _);
+                Logger.LogInformation("Job {JobId} removed", cachedJobId);
+            }
+        }
+
+        // Add or update jobs in Hangfire based on the database profiles
+        foreach (var profile in profiles)
+        {
+            if (ProfileCache.TryGetValue(profile.JobId(), out var currentProfile)
+                && currentProfile!.Schedule == profile.Schedule)
+                continue;
+
+            // Add or update recurring job using MediatR command
+            JobManager.AddOrUpdate<IMediator>(
+                profile.JobId(),
+                mediator => mediator.Send(profile.ToJob(), stoppingToken),
+                profile.Schedule,
+                new RecurringJobOptions
+                {
+                    TimeZone = TimeZoneInfo.Local
+                }
+            );
+
+            // Store/update in local cache
+            ProfileCache.AddOrUpdate(profile.JobId(), profile);
+
+            Logger.LogInformation("Job {JobId} registered with schedule: {Schedule}",
+                profile.JobId(), profile.Schedule);
+        }
+    }
+}