Refactor and update various components of EchoHub.Server

- Updated launchSettings.json for consistency.
- Refactored FileValidationHelper to improve image validation logic.
- Enhanced ServerDirectoryService for better connection handling and user count updates.
- Improved DatabaseSetup for legacy database handling and seeding default channels.
- Refined FirstRunSetup to ensure JWT secret generation.
- Removed appsettings.Development.json as it is no longer needed.
- Updated EchoHub.Tests project file for consistency.
- Added unit tests for FileValidationHelper and PresenceTracker with improved assertions.
- Updated ValidationConstantsTests to ensure regex validations are correct.
- Cleaned up solution file formatting for better readability.

src/EchoHub.Client/AsyncRunner.cs

@@ -1,32 +1,32 @@
-using Serilog;
-using Terminal.Gui.App;
-
-namespace EchoHub.Client;
-
-/// <summary>
-/// Eliminates repeated Task.Run/try/catch/app.Invoke(ShowError) boilerplate.
-/// Runs async work on a background thread and routes exceptions to the UI.
-/// </summary>
-public static class AsyncRunner
-{
-    public static void Run(
-        IApplication app,
-        Func<Task> work,
-        Action<string> showError,
-        string errorPrefix,
-        string? logContext = null)
-    {
-        Task.Run(async () =>
-        {
-            try
-            {
-                await work();
-            }
-            catch (Exception ex)
-            {
-                Log.Error(ex, "{Context} failed", logContext ?? errorPrefix);
-                app.Invoke(() => showError($"{errorPrefix}: {ex.Message}"));
-            }
-        });
-    }
-}
+using Serilog;
+using Terminal.Gui.App;
+
+namespace EchoHub.Client;
+
+/// <summary>
+/// Eliminates repeated Task.Run/try/catch/app.Invoke(ShowError) boilerplate.
+/// Runs async work on a background thread and routes exceptions to the UI.
+/// </summary>
+public static class AsyncRunner
+{
+    public static void Run(
+        IApplication app,
+        Func<Task> work,
+        Action<string> showError,
+        string errorPrefix,
+        string? logContext = null)
+    {
+        Task.Run(async () =>
+        {
+            try
+            {
+                await work();
+            }
+            catch (Exception ex)
+            {
+                Log.Error(ex, "{Context} failed", logContext ?? errorPrefix);
+                app.Invoke(() => showError($"{errorPrefix}: {ex.Message}"));
+            }
+        });
+    }
+}