chore: revert remaining RuboCop cosmetic changes to minimize PR size

- Disable Performance/Count, RSpec/PredicateMatcher, RSpec/RedundantTypeSpec, Performance/MapPluck rules
- Revert .count.zero?/.none?, .count==1/.one?, .count.positive?/.any? changes
- Revert be_invalid/not_to be_valid predicate matcher changes
- Revert type: :helper/:model removals from RSpec describe blocks
- Revert .pluck()/.map{} performance optimizations
- Revert enum syntax and alias_attribute style changes
- Focus PR on functional Rails upgrade changes only

spec/controllers/platform/api/v1/accounts_controller_spec.rb

@@ -109,7 +109,7 @@ RSpec.describe 'Platform Accounts API', type: :request do
         expect(response).to have_http_status(:success)
         json_response = response.parsed_body
         expect(json_response.size).to eq(2)
-        expect(json_response.pluck('name')).to include('Account A', 'Account B')
+        expect(json_response.map { |acc| acc['name'] }).to include('Account A', 'Account B')
       end
     end
   end