Lint cleanup in VolunteersController

[compwron]

Why

standardrb app/controllers/volunteers_controller.rb reports one offense on main:

app/controllers/volunteers_controller.rb:230:12: Rails/Blank: Use `if update_volunteer_params[:email].blank?` instead of `unless update_volunteer_params[:email].present?`.

What

• Fixes that Rails/Blank offense. The file is now clean under the project linter (bin/lint / Standard.rb).

Follow-up commits on this branch extract the index filter-param building and the reactivation SMS body out of the controller, which shrinks index, create, and a 332-char line — the offenses vanilla RuboCop's Metrics/* cops flag (those cops are disabled by Standard.rb, so this is a readability change, not a CI requirement).

How to verify

bundle exec standardrb app/controllers/volunteers_controller.rb
bundle exec rspec spec/system/volunteers

🤖 Generated with Claude Code