feat(zed): add Nord theme and project settings

Theme file lives in .zed/nord.json; arty zed:theme:install copies it
to the Windows Zed themes directory via wslpath.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

arty.yml

@@ -55,6 +55,7 @@ scripts:
     go install github.com/mikefarah/yq/v4@latest
     go install github.com/charmbracelet/glow/v2@latest
   go:clean: go clean -cache && go clean -modcache
+  zed:theme:install: cp .zed/nord.json "$(wslpath "$(cmd.exe /c 'echo %APPDATA%' 2>/dev/null | tr -d '\r')")/Zed/themes/nord.json"
   vscode:extensions: |
     code --install-extension editorconfig.editorconfig
   micro:install: