Spending figures were inflated: Fuliza repayments double-counted the
already-counted borrow-backed purchase, M-Shwari/KCB deposits counted
own-money savings as spending, and reversed transactions never came
back out of the total. All spending queries now exclude these.
Also adds a month-by-month breakdown card to Trends (12 months,
delta vs previous month) and captures the credited amount on
standard-format reversal SMS instead of recording 0.0.
