Expense Tracker

v3: add income, categories, savings (income minus spending), month and all-time views, goal, recent list, history with search and edit, CSV export. Old expenses kept as Uncategorized.

Fix: the closed Add form no longer keeps the last expense's text, so nothing stale is left behind after saving.

First version: add an expense with an amount and a note, see the list, delete one, and see the total.