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 In doing so, some parts of the codebase have become outdated, unnecessary, or overly-complex as a natural result of this feature prioritization.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

@@ -67,30 +67,13 @@ class Account::EntryTest < ActiveSupport::TestCase
     assert_equal 0, family.entries.search(params).size
   end
 
-  test "can calculate totals for a group of transactions" do
-    family = families(:empty)
-    account = family.accounts.create! name: "Test", balance: 0, currency: "USD", accountable: Depository.new
-    create_transaction(account: account, amount: 100)
-    create_transaction(account: account, amount: 100)
-    create_transaction(account: account, amount: -500)
-
-    totals = family.entries.stats("USD")
-
-    assert_equal 3, totals.count
-    assert_equal 500, totals.income_total
-    assert_equal 200, totals.expense_total
-    assert_equal "USD", totals.currency
-  end
-
-  test "active scope only returns entries from active, non-scheduled-for-deletion accounts" do
+  test "active scope only returns entries from active accounts" do
     # Create transactions for all account types
     active_transaction = create_transaction(account: accounts(:depository), name: "Active transaction")
     inactive_transaction = create_transaction(account: accounts(:credit_card), name: "Inactive transaction")
-    deletion_transaction = create_transaction(account: accounts(:investment), name: "Scheduled for deletion transaction")
 
     # Update account statuses
     accounts(:credit_card).update!(is_active: false)
-    accounts(:investment).update!(scheduled_for_deletion: true)
 
     # Test the scope
     active_entries = Account::Entry.active
@@ -100,8 +83,5 @@ class Account::EntryTest < ActiveSupport::TestCase
 
     # Should not include entry from inactive account
     assert_not_includes active_entries, inactive_transaction
-
-    # Should not include entry from account scheduled for deletion
-    assert_not_includes active_entries, deletion_transaction
   end
 end