Fix Rider WinForms Designer Build Locks

Problem

Rider's WinForms Designer locks files, preventing builds.

Solution

1. File → Settings (Ctrl+Alt+S)
2. Tools → Windows Forms Designer
3. Uncheck "Enable Windows Forms Designer"
4. Apply and restart Rider

Emergency Fix

Kill locked processes:

taskkill /IM dotnet.exe /F

Alternative

Use Visual Studio for form design, Rider for code.