Add comprehensive unit test coverage for controllers, models, and services

- Translate French comments to English in controllers and tests
- Fix test failures: route helpers, validations, MySQL transaction issues
- Add Timecop for time-dependent tests and update database config for isolation

app/controllers/application_controller.rb

@@ -38,8 +38,6 @@ class ApplicationController < ActionController::Base
     # Skip for API endpoints
     controller_name.start_with?("api/") ||
     # Skip for health checks
-    controller_name == "rails/health" ||
-    # Skip for home page (when not signed in)
-    (controller_name == "pages" && action_name == "home")
+    controller_name == "rails/health"
   end
 end