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 In doing so, some parts of the codebase have become outdated, unnecessary, or overly-complex as a natural result of this feature prioritization.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/transactions/_summary.html.erb

@@ -1,19 +1,19 @@
 <%# locals: (totals:) %>
-<div class="grid grid-cols-3 bg-white rounded-xl border border-alpha-black-25 shadow-xs divide-x divide-alpha-black-100">
+<div class="grid grid-cols-3 bg-white rounded-xl shadow-border-xs divide-x divide-alpha-black-100">
   <div class="p-4 space-y-2">
     <p class="text-sm text-secondary">Total transactions</p>
-    <p class="text-primary font-medium text-xl" id="total-transactions"><%= totals.count %></p>
+    <p class="text-primary font-medium text-xl" id="total-transactions"><%= totals.transactions_count %></p>
   </div>
   <div class="p-4 space-y-2">
     <p class="text-sm text-secondary">Income</p>
     <p class="text-primary font-medium text-xl" id="total-income">
-      <%= format_money Money.new(totals.income_total, totals.currency) %>
+      <%= totals.income_money.format %>
     </p>
   </div>
   <div class="p-4 space-y-2">
     <p class="text-sm text-secondary">Expenses</p>
     <p class="text-primary font-medium text-xl" id="total-expense">
-      <%= format_money Money.new(totals.expense_total, totals.currency) %>
+      <%= totals.expense_money.format %>
     </p>
   </div>
 </div>