Change Rakefile to run json checks first then all checks

Rakefile

@@ -1,22 +1,31 @@
 require 'yaml'
 
-namespace :lint do
-  begin
-    require 'rspec/core/rake_task'
+begin
+  require 'rspec/core/rake_task'
+rescue LoadError
+  warn "Warning: RSpec is not installed. Please run `gem install rspec` to install RSpec."
+end
+
+if defined?(RSpec::Core::RakeTask)
+  namespace :lint do
+    desc "Lint reports (excluding schema validation)"
+    RSpec::Core::RakeTask.new(:yaml) do |t|
+      t.exclude_pattern = 'spec/schema_validation_spec.rb'
+    end
 
-    RSpec::Core::RakeTask.new(:yaml)
-  rescue LoadError => e
-    task :spec do
-      abort "Please run `gem install rspec` to install RSpec."
+    desc "Validate report schema"
+    RSpec::Core::RakeTask.new(:schema) do |t|
+      t.pattern = 'spec/schema_validation_spec.rb'
     end
   end
+
+  desc "Run all linting tasks"
+  task :lint    => [ 'lint:schema', 'lint:yaml' ]
+  task :default => [ :lint ]
 end
 
 desc "Sync GitHub RubyGem Advisories into this project"
 task :sync_github_advisories, [:gem_name] do |_, args|
   require_relative "lib/github_advisory_sync"
   GitHub::GitHubAdvisorySync.sync(gem_name: args[:gem_name])
 end
-
-task :lint    => ['lint:yaml']
-task :default => :lint