Fix rubocop linting issues in API chat endpoints

- Fix trailing whitespace
- Add missing final newlines
- Fix array bracket spacing
- Auto-corrected all layout issues

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

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

test/controllers/api/v1/chats_controller_test.rb

@@ -116,7 +116,7 @@ class Api::V1::ChatsControllerTest < ActionDispatch::IntegrationTest
     plain_key = ApiKey.generate_secure_key
     api_key = @user.api_keys.build(
       name: "Test API Key",
-      scopes: ["read_write"]
+      scopes: [ "read_write" ]
     )
     api_key.key = plain_key
     api_key.save!