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 In doing so, some parts of the codebase have become outdated, unnecessary, or overly-complex as a natural result of this feature prioritization.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

@@ -1,26 +1,11 @@
 class AccountsController < ApplicationController
-  layout :with_sidebar
-
-  before_action :set_account, only: %i[sync]
+  before_action :set_account, only: %i[sync chart sparkline]
 
   def index
-    @manual_accounts = Current.family.accounts.manual.alphabetically
-    @plaid_items = Current.family.plaid_items.ordered
-  end
+    @manual_accounts = family.accounts.manual.alphabetically
+    @plaid_items = family.plaid_items.ordered
 
-  def summary
-    @period = Period.from_param(params[:period])
-    snapshot = Current.family.snapshot(@period)
-    @net_worth_series = snapshot[:net_worth_series]
-    @asset_series = snapshot[:asset_series]
-    @liability_series = snapshot[:liability_series]
-    @accounts = Current.family.accounts.active
-    @account_groups = @accounts.by_group(period: @period, currency: Current.family.currency)
-  end
-
-  def list
-    @period = Period.from_param(params[:period])
-    render layout: false
+    render layout: "settings"
   end
 
   def sync
@@ -32,20 +17,27 @@ class AccountsController < ApplicationController
   end
 
   def chart
-    @account = Current.family.accounts.find(params[:id])
     render layout: "application"
   end
 
+  def sparkline
+    render layout: false
+  end
+
   def sync_all
-    unless Current.family.syncing?
-      Current.family.sync_later
+    unless family.syncing?
+      family.sync_later
     end
 
     redirect_to accounts_path
   end
 
   private
+    def family
+      Current.family
+    end
+
     def set_account
-      @account = Current.family.accounts.find(params[:id])
+      @account = family.accounts.find(params[:id])
     end
 end