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.Tests/EchoHub.Tests.csproj

@@ -1,25 +1,25 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
-  <PropertyGroup>
-    <TargetFramework>net10.0</TargetFramework>
-    <ImplicitUsings>enable</ImplicitUsings>
-    <Nullable>enable</Nullable>
-    <IsPackable>false</IsPackable>
-    <IsTestProject>true</IsTestProject>
-  </PropertyGroup>
-
-  <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.*" />
-    <PackageReference Include="xunit" Version="2.*" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.*">
-      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-      <PrivateAssets>all</PrivateAssets>
-    </PackageReference>
-  </ItemGroup>
-
-  <ItemGroup>
-    <ProjectReference Include="..\EchoHub.Core\EchoHub.Core.csproj" />
-    <ProjectReference Include="..\EchoHub.Server\EchoHub.Server.csproj" />
-  </ItemGroup>
-
-</Project>
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.*" />
+    <PackageReference Include="xunit" Version="2.*" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.*">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\EchoHub.Core\EchoHub.Core.csproj" />
+    <ProjectReference Include="..\EchoHub.Server\EchoHub.Server.csproj" />
+  </ItemGroup>
+
+</Project>