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/routes.rb

@@ -12,9 +12,12 @@ Rails.application.routes.draw do
   # Defines the root path route ("/")
   root "pages#home"
 
-  # parties page
-  get "parties",              to: "parties#index",  as: "parties"
-  get "parties/:slug.:id",        to: "parties#show",   as: "party"
+  # Pages
+  get "dashboard", to: "pages#dashboard", as: "dashboard"
+
+  # Parties
+  get "parties",            to: "parties#index",  as: "parties"
+  get "parties/:slug.:id",  to: "parties#show",   as: "party"
 
   # Routes for devise authentication Gem
   # Bind devise to user