create colour scheme tructure

lua/paper-tonic-modern/groups/editor.lua

@@ -0,0 +1,9 @@
+-- Paper Tonic Modern - Editor Highlight Groups
+-- Base Vim/Neovim UI elements
+
+local colors = require('paper-tonic-modern.colors')
+
+return {
+  -- Core editor elements (to be implemented in Phase 11.4)
+  Normal = { fg = colors.fg, bg = colors.bg },
+}