chore: fix nuget package resolution for local windows builds

- Add NuGet.Config with explicit globalPackagesFolder using %USERPROFILE%
  to prevent Docker-generated obj/ files (with /root/.nuget/packages/)
  from breaking Rider/local dotnet builds
- Restore Microsoft.AspNetCore.OpenApi to Directory.Packages.props
  (was accidentally removed; required by Web project)

Ref: IT-628

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Directory.Packages.props

@@ -16,8 +16,8 @@
         <PackageVersion Include="Microsoft.Extensions.Hosting.Abstractions" Version="10.0.6" />
         <PackageVersion Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.6" />
         <PackageVersion Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.6" />
-        <PackageVersion Include="Microsoft.AspNetCore.OpenApi" Version="10.0.6" />
         <PackageVersion Include="Scalar.AspNetCore" Version="2.14.9" />
+        <PackageVersion Include="Microsoft.AspNetCore.OpenApi" Version="10.0.6" />
 
         <!-- Serilog -->
         <PackageVersion Include="Serilog" Version="4.2.0" />

NuGet.Config

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <config>
+    <add key="globalPackagesFolder" value="%USERPROFILE%\.nuget\packages" />
+  </config>
+  <packageSources>
+    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
+  </packageSources>
+</configuration>