Fix CI matrix on Ruby 3.x + Rails 5.2/6.0/6.1: require "logger" before rails

Phase 2a's integration test scaffolding (spec/rails_helper.rb and
spec/dummy/config/application.rb) both do `require "rails"` eagerly.
ActiveSupport 5.2/6.0/6.1 references `Logger::Severity` inside
lib/active_support/logger_thread_safe_level.rb without first requiring
"logger" — this works on Ruby 2.x (Logger was more eagerly autoloaded)
but raises

    NameError: uninitialized constant ActiveSupport::LoggerThreadSafeLevel::Logger

on Ruby 3.x. Rails 7.0+ fixed this at the ActiveSupport level; older
Rails combined with Ruby 3.x needs an explicit `require "logger"` before
any AS/Rails code runs.

Matrix cells affected (from the 0.5.0 publish cycle's CI run 24290748435):
- Ruby 2.7 x Rails 6.0, 6.1
- Ruby 3.0 x Rails 5.2, 6.0, 6.1
- Ruby 3.1 x Rails 6.0, 6.1
- Ruby 3.2 x Rails 6.1
- Ruby 3.3 x Rails 6.1

All Rails 7.0+ cells (all Ruby versions) pass unchanged.

Fix is test-support-only — `spec/rails_helper.rb` and
`spec/dummy/config/application.rb` both gain a single `require "logger"`
at the top, before their `require "rails"`. Zero runtime impact on the
shipped gems (these files are not in spec.files for either gem).

This is a pure CI cleanup for 0.5.0 — no new release needed.

Author: antarr

spec/dummy/config/application.rb

@@ -2,6 +2,13 @@
 
 require_relative "boot"
 
+# Ruby 3.x + ActiveSupport 5.2/6.0/6.1 compat: Logger must be loaded before
+# any active_support require, otherwise logger_thread_safe_level.rb raises
+# `NameError: uninitialized constant ActiveSupport::LoggerThreadSafeLevel::Logger`.
+# Rails 7.0+ includes its own `require "logger"` so this is only needed for
+# the older-Rails matrix cells.
+require "logger"
+
 require "rails"
 require "action_controller/railtie"
 

spec/rails_helper.rb

@@ -4,6 +4,16 @@
 # Rack::Test for request dispatch. Unit specs continue to use spec_helper.rb
 # (no Rails boot).
 
+# Load stdlib Logger BEFORE any Rails/ActiveSupport require. ActiveSupport
+# 5.2/6.0/6.1 references `Logger::Severity` inside
+# `lib/active_support/logger_thread_safe_level.rb` without first requiring
+# "logger", which works on Ruby 2.x (Logger was autoloaded more eagerly)
+# but raises `NameError: uninitialized constant ActiveSupport::LoggerThreadSafeLevel::Logger`
+# on Ruby 3.x. Rails 7.0+ fixed this at the AS level; older Rails combined
+# with Ruby 3.x needs this workaround. The matrix cells affected are
+# Ruby 3.0-3.3 × Rails 5.2/6.0/6.1 in .github/workflows/ci.yml.
+require "logger"
+
 # .rspec has `--require spec_helper`, so spec_helper is auto-loaded before
 # rails_helper. spec_helper calls `require "mysql_genius"` when Rails is not
 # yet defined, so lib/mysql_genius.rb skips `require "mysql_genius/engine"`