feat: initialize WinUI 3 WebView migration

.gitignore

@@ -0,0 +1,40 @@
+# Visual Studio / .NET
+.vs/
+**/bin/
+**/obj/
+artifacts/
+TestResults/
+*.user
+*.suo
+*.userosscache
+*.sln.docstates
+
+# MSIX build output and signing material
+AppPackages/
+BundleArtifacts/
+*.appx
+*.appxbundle
+*.msix
+*.msixbundle
+*.msixupload
+*.pfx
+*.p12
+*.snk
+
+# Local settings and secrets
+Config/appsettings.local.json
+Config/*.secrets.json
+*.local.ini
+.env
+.env.*
+!.env.example
+
+# Web tooling (if introduced later)
+node_modules/
+dist/
+
+# OS / editors
+.DS_Store
+Thumbs.db
+.idea/
+.vscode/