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 In doing so, some parts of the codebase have become outdated, unnecessary, or overly-complex as a natural result of this feature prioritization.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

test/system/accounts_test.rb

@@ -72,11 +72,14 @@ class AccountsTest < ApplicationSystemTestCase
   private
 
     def open_new_account_modal
-      click_link "sidebar-new-account"
+      within "[data-controller='tabs']" do
+        click_button "All"
+        click_link "New account"
+      end
     end
 
     def assert_account_created(accountable_type, &block)
-      click_link humanized_accountable(accountable_type)
+      click_link Accountable.from_type(accountable_type).display_name.singularize
       click_link "Enter account balance" if accountable_type.in?(%w[Depository Investment Crypto Loan CreditCard])
 
       account_name = "[system test] #{accountable_type} Account"
@@ -88,8 +91,10 @@ class AccountsTest < ApplicationSystemTestCase
 
       click_button "Create Account"
 
-      find("details", text: humanized_accountable(accountable_type)).click
-      assert_text account_name
+      within "[data-controller='tabs']" do
+        find("details", text: Accountable.from_type(accountable_type).display_name).click
+        assert_text account_name
+      end
 
       visit accounts_url
       assert_text account_name
@@ -109,6 +114,6 @@ class AccountsTest < ApplicationSystemTestCase
     end
 
     def humanized_accountable(accountable_type)
-      accountable_type.constantize.model_name.human
+      Accountable.from_type(accountable_type).display_name.singularize
     end
 end