New Design System + Codebase Refresh (#1823)

Since the very first 0.1.0-alpha.1 release, we've been moving quickly to add new features to the Maybe app. In doing so, some parts of the codebase have become outdated, unnecessary, or overly-complex as a natural result of this feature prioritization.

Now that "core" Maybe is complete, we're moving into a second phase of development where we'll be working hard to improve the accuracy of existing features and build additional features on top of "core". This PR is a quick overhaul of the existing codebase aimed to:

- Establish the brand new and simplified dashboard view (pictured above)
- Establish and move towards the conventions introduced in Cursor rules and project design overview #1788
- Consolidate layouts and improve the performance of layout queries
- Organize the core models of the Maybe domain (i.e. Account::Entry, Account::Transaction, etc.) and break out specific traits of each model into dedicated concerns for better readability
- Remove stale / dead code from codebase
- Remove overly complex code paths in favor of simpler ones

app/views/shared/_app_version.html.erb

@@ -1,6 +1,3 @@
-<div class="flex items-center py-0.5 px-0.5 gap-1 fixed bottom-2 right-2 shadow-xs border border-alpha-black-50 rounded-md bg-white">
+<div class="flex items-center py-0.5 px-0.5 gap-1 fixed right-1 top-1 shadow-xs border border-alpha-black-50 rounded-md bg-white">
   <p class="text-xs text-secondary pl-2">Version: <%= Maybe.version.to_release_tag %></p>
-  <%= link_to settings_hosting_path, class: "flex gap-1 items-center hover:bg-gray-50 rounded-md p-2" do %>
-    <%= lucide_icon("settings", class: "w-4 h-4 text-secondary shrink-0") %>
-  <% end %>
 </div>