feat: implement flash messages system with auto-dismiss notifications

- Add flash message helper and styles for consistent notifications
- Replace Devise error messages with flash-based notifications
- Add dashboard page with event statistics
- Configure SMTP settings for development and production
- Update authentication controllers to use flash messages
- Add JavaScript controller for auto-dismiss functionality

config/environments/production.rb

@@ -60,14 +60,17 @@ Rails.application.configure do
   # Set host to be used by links generated in mailer templates.
   config.action_mailer.default_url_options = { host: "example.com" }
 
-  # Specify outgoing SMTP server. Remember to add smtp/* credentials via rails credentials:edit.
-  # config.action_mailer.smtp_settings = {
-  #   user_name: Rails.application.credentials.dig(:smtp, :user_name),
-  #   password: Rails.application.credentials.dig(:smtp, :password),
-  #   address: "smtp.example.com",
-  #   port: 587,
-  #   authentication: :plain
-  # }
+  # Configure SMTP settings using environment variables
+  config.action_mailer.delivery_method = :smtp
+  config.action_mailer.smtp_settings = {
+    address: ENV.fetch("SMTP_ADDRESS", "smtp.example.com"),
+    port: ENV.fetch("SMTP_PORT", 587),
+    user_name: ENV.fetch("SMTP_USERNAME", ""),
+    password: ENV.fetch("SMTP_PASSWORD", ""),
+    authentication: ENV.fetch("SMTP_AUTHENTICATION", "plain"),
+    domain: ENV.fetch("SMTP_DOMAIN", "example.com"),
+    enable_starttls_auto: ENV.fetch("SMTP_STARTTLS", true)
+  }
 
   # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
   # the I18n.default_locale when a translation cannot be found).