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 In doing so, some parts of the codebase have become outdated, unnecessary, or overly-complex as a natural result of this feature prioritization.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

@@ -1,9 +1,11 @@
 <%# locals: (family:, year:) %>
 
 <%= turbo_frame_tag "budget_picker" do %>
-  <div class="bg-white shadow-md border border-alpha-black-25 p-3 rounded-xl space-y-4">
+  <div class="bg-white shadow-border-xs p-3 rounded-xl space-y-4">
     <div class="flex items-center gap-2 justify-between">
-      <% if year > family.oldest_entry_date.year %>
+      <% last_month_of_previous_year = Date.new(year - 1, 12, 1) %>
+
+      <% if Budget.budget_date_valid?(last_month_of_previous_year, family: family) %>
         <%= link_to picker_budgets_path(year: year - 1), data: { turbo_frame: "budget_picker" }, class: "p-2 flex items-center justify-center hover:bg-alpha-black-25 rounded-md" do %>
           <%= lucide_icon "chevron-left", class: "w-5 h-5 shrink-0 text-secondary" %>
         <% end %>
@@ -17,7 +19,9 @@
         <%= year %>
       </span>
 
-      <% if year < Date.current.year %>
+      <% first_month_of_next_year = Date.new(year + 1, 1, 1) %>
+
+      <% if Budget.budget_date_valid?(first_month_of_next_year, family: family) %>
         <%= link_to picker_budgets_path(year: year + 1), data: { turbo_frame: "budget_picker" }, class: "p-2 flex items-center justify-center hover:bg-alpha-black-25 rounded-md" do %>
           <%= lucide_icon "chevron-right", class: "w-5 h-5 shrink-0 text-secondary" %>
         <% end %>
@@ -29,17 +33,12 @@
     </div>
 
     <div class="grid grid-cols-3 gap-2 text-sm text-center font-medium">
-      <% Date::ABBR_MONTHNAMES.compact.each_with_index do |month_name, index| %>
-        <% month_number = index + 1 %>
-        <% start_date = Date.new(year, month_number) %>
-        <% budget = family.budgets.for_date(start_date) %>
+      <% Date::ABBR_MONTHNAMES.compact.each do |month_name| %>
+        <% date = Date.strptime("#{month_name}-#{year}", "%b-%Y") %>
+        <% param_key = Budget.date_to_param(date) %>
 
-        <% if budget %>
-          <%= link_to month_name, budget_path(budget), data: { turbo_frame: "_top" }, class: "block px-3 py-2 text-sm text-primary hover:bg-gray-100 rounded-md" %>
-        <% elsif start_date >= family.oldest_entry_date.beginning_of_month && start_date <= Date.current %>
-          <%= button_to budgets_path(budget: { start_date: start_date }), data: { turbo_frame: "_top" }, class: "block w-full px-3 py-2 text-primary hover:bg-gray-100 rounded-md" do %>
-            <%= month_name %>
-          <% end %>
+        <% if Budget.budget_date_valid?(date, family: family) %>
+          <%= link_to month_name, budget_path(param_key), data: { turbo_frame: "_top" }, class: "block px-3 py-2 text-sm text-primary hover:bg-gray-100 rounded-md" %>
         <% else %>
           <span class="px-3 py-2 text-subdued rounded-md"><%= month_name %></span>
         <% end %>