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

app/helpers/flash_messages_helper.rb

@@ -0,0 +1,34 @@
+module FlashMessagesHelper
+  def flash_class(type)
+    case type.to_s
+    when 'notice' then 'flash-message-success'
+    when 'success' then 'flash-message-success'
+    when 'error' then 'flash-message-error'
+    when 'alert' then 'flash-message-error'
+    when 'warning' then 'flash-message-warning'
+    when 'info' then 'flash-message-info'
+    else "flash-message-#{type}"
+    end
+  end
+
+  def flash_icon(type)
+    case type.to_s
+    when 'notice', 'success'
+      content_tag :svg, class: "h-5 w-5 text-green-400", fill: "currentColor", viewBox: "0 0 20 20" do
+        content_tag :path, "", "fill-rule": "evenodd", "d": "M10 18a8 8 0 100-16 8 8 0 000 16zm3.707-9.293a1 1 0 00-1.414-1.414L9 10.586 7.707 9.293a1 1 0 00-1.414 1.414l2 2a1 1 0 001.414 0l4-4z", "clip-rule": "evenodd"
+      end
+    when 'error', 'alert'
+      content_tag :svg, class: "h-5 w-5 text-red-400", fill: "currentColor", viewBox: "0 0 20 20" do
+        content_tag :path, "", "fill-rule": "evenodd", "d": "M10 18a8 8 0 100-16 8 8 0 000 16zM8.707 7.293a1 1 0 00-1.414 1.414L8.586 10l-1.293 1.293a1 1 0 101.414 1.414L10 11.414l1.293 1.293a1 1 0 001.414-1.414L11.414 10l1.293-1.293a1 1 0 00-1.414-1.414L10 8.586 8.707 7.293z", "clip-rule": "evenodd"
+      end
+    when 'warning'
+      content_tag :svg, class: "h-5 w-5 text-yellow-400", fill: "currentColor", viewBox: "0 0 20 20" do
+        content_tag :path, "", "fill-rule": "evenodd", "d": "M8.257 3.099c.765-1.36 2.722-1.36 3.486 0l5.58 9.92c.75 1.334-.213 2.98-1.742 2.98H4.42c-1.53 0-2.493-1.646-1.743-2.98l5.58-9.92zM11 13a1 1 0 11-2 0 1 1 0 012 0zm-1-8a1 1 0 00-1 1v3a1 1 0 002 0V6a1 1 0 00-1-1z", "clip-rule": "evenodd"
+      end
+    else
+      content_tag :svg, class: "h-5 w-5 text-blue-400", fill: "currentColor", viewBox: "0 0 20 20" do
+        content_tag :path, "", "fill-rule": "evenodd", "d": "M18 10a8 8 0 11-16 0 8 8 0 0116 0zm-7-4a1 1 0 11-2 0 1 1 0 012 0zM9 9a1 1 0 000 2v3a1 1 0 001 1h1a1 1 0 100-2v-3a1 1 0 00-1-1H9z", "clip-rule": "evenodd"
+      end
+    end
+  end
+end