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 In doing so, some parts of the codebase have become outdated, unnecessary, or overly-complex as a natural result of this feature prioritization.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

lib/money/formatting.rb

@@ -1,11 +1,11 @@
 module Money::Formatting
-  # Fallback formatting.  For advanced formatting, use Rails number_to_currency helper.
-  def format
-    whole_part, fractional_part = sprintf("%.#{currency.default_precision}f", amount).split(".")
-    whole_with_delimiters = whole_part.chars.to_a.reverse.each_slice(3).map(&:join).join(currency.delimiter).reverse
-    formatted_amount = "#{whole_with_delimiters}#{currency.separator}#{fractional_part}"
+  include ActiveSupport::NumberHelper
 
-    currency.default_format.gsub("%n", formatted_amount).gsub("%u", currency.symbol)
+  def format(options = {})
+    locale = options[:locale] || I18n.locale
+    default_opts = format_options(locale)
+
+    number_to_currency(amount, default_opts.merge(options))
   end
   alias_method :to_s, :format