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.Server/Controllers/FilesController.cs

@@ -1,40 +1,40 @@
-using EchoHub.Core.DTOs;
-using EchoHub.Server.Services;
-using Microsoft.AspNetCore.Authorization;
-using Microsoft.AspNetCore.Mvc;
-using Microsoft.AspNetCore.RateLimiting;
-
-namespace EchoHub.Server.Controllers;
-
-[ApiController]
-[Route("api/files")]
-[Authorize]
-[EnableRateLimiting("general")]
-public class FilesController(FileStorageService fileStorage) : ControllerBase
-{
-    [HttpGet("{fileId}")]
-    public IActionResult GetFile(string fileId)
-    {
-        if (!Guid.TryParse(fileId, out _))
-            return BadRequest(new ErrorResponse("Invalid file identifier."));
-
-        var filePath = fileStorage.GetFilePath(fileId);
-
-        if (filePath is null)
-            return NotFound(new ErrorResponse("File not found."));
-
-        var contentType = Path.GetExtension(filePath).ToLowerInvariant() switch
-        {
-            ".jpg" or ".jpeg" => "image/jpeg",
-            ".png" => "image/png",
-            ".gif" => "image/gif",
-            ".webp" => "image/webp",
-            ".pdf" => "application/pdf",
-            ".txt" => "text/plain",
-            _ => "application/octet-stream"
-        };
-
-        var fileName = Path.GetFileName(filePath);
-        return PhysicalFile(filePath, contentType, fileName);
-    }
-}
+using EchoHub.Core.DTOs;
+using EchoHub.Server.Services;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.RateLimiting;
+
+namespace EchoHub.Server.Controllers;
+
+[ApiController]
+[Route("api/files")]
+[Authorize]
+[EnableRateLimiting("general")]
+public class FilesController(FileStorageService fileStorage) : ControllerBase
+{
+    [HttpGet("{fileId}")]
+    public IActionResult GetFile(string fileId)
+    {
+        if (!Guid.TryParse(fileId, out _))
+            return BadRequest(new ErrorResponse("Invalid file identifier."));
+
+        var filePath = fileStorage.GetFilePath(fileId);
+
+        if (filePath is null)
+            return NotFound(new ErrorResponse("File not found."));
+
+        var contentType = Path.GetExtension(filePath).ToLowerInvariant() switch
+        {
+            ".jpg" or ".jpeg" => "image/jpeg",
+            ".png" => "image/png",
+            ".gif" => "image/gif",
+            ".webp" => "image/webp",
+            ".pdf" => "application/pdf",
+            ".txt" => "text/plain",
+            _ => "application/octet-stream"
+        };
+
+        var fileName = Path.GetFileName(filePath);
+        return PhysicalFile(filePath, contentType, fileName);
+    }
+}