DEV: Fix SimpleCov integration and add rake critique task

Move SimpleCov.start into spec_helper.rb so it loads before application
code. The previous .simplecov file loaded too late for SimpleCov to
detect RSpec, resulting in empty coverage data for RubyCritic.

Add `rake critique` task that runs tests with coverage then RubyCritic.

Author: gschlager

.simplecov

@@ -15,4 +15,10 @@ task :fix do
   sh "bundle exec stree write '**/*.rb' '**/*.rake' Gemfile Rakefile *.gemspec"
 end
 
+desc "Run RubyCritic with coverage (runs tests first)"
+task :critique do
+  sh "COVERAGE=1 bundle exec rspec --format progress"
+  sh "bundle exec rubycritic"
+end
+
 task default: %i[fix spec]

Rakefile

@@ -1,6 +1,14 @@
 # frozen_string_literal: true
 
-require "simplecov" if ENV["COVERAGE"]
+if ENV["COVERAGE"]
+  require "simplecov"
+  SimpleCov.start do
+    command_name "RSpec"
+    add_filter "/examples/"
+    add_filter "/spec/"
+  end
+end
+
 require "markbridge/all"
 
 SPEC_ROOT = Pathname(__dir__)