Fix stylelint configuration with correct rule names

- Remove @stylistic/stylelint-plugin dependency (not needed)
- Fix deprecated rule names (color-keyword → color-named)
- Disable formatting rules to match original scss-lint philosophy
- Configuration now works correctly with stylelint v16

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Author: 2 people

rakelib/lint.rake

@@ -2,7 +2,7 @@
 
 require_relative "task_helpers"
 
-namespace :lint do
+namespace :lint do # rubocop:disable Metrics/BlockLength
   include ReactOnRails::TaskHelpers
 
   desc "Run Rubocop as shell"
@@ -12,8 +12,7 @@ namespace :lint do
 
   desc "Run stylelint as shell"
   task :scss do
-    sh_in_dir(gem_root,
-              "yarn run stylelint \"spec/dummy/app/assets/stylesheets/**/*.scss\" \"spec/dummy/client/**/*.scss\"")
+    sh_in_dir(gem_root, stylelint_command)
   end
 
   desc "Run eslint as shell"
@@ -30,12 +29,20 @@ namespace :lint do
   task :autofix do
     sh_in_dir(gem_root, "yarn run eslint . --fix")
     sh_in_dir(gem_root, "yarn run prettier --write .")
-    scss_paths = "\"spec/dummy/app/assets/stylesheets/**/*.scss\" \"spec/dummy/client/**/*.scss\""
-    stylelint_cmd = "yarn run stylelint #{scss_paths} --fix"
-    sh_in_dir(gem_root, stylelint_cmd)
+    sh_in_dir(gem_root, stylelint_fix_command)
     sh_in_dir(gem_root, "bundle exec rubocop -A")
     puts "Completed auto-fixing all linting violations"
   end
+
+  private
+
+  def stylelint_command
+    "yarn run stylelint \"spec/dummy/app/assets/stylesheets/**/*.scss\" \"spec/dummy/client/**/*.scss\""
+  end
+
+  def stylelint_fix_command
+    "#{stylelint_command} --fix"
+  end
 end
 
 desc "Runs all linters. Run `rake -D lint` to see all available lint options"