NizKhata Android v1.10.2

A card bill that has already been paid is not raised again (#113)

Setting up a billing cycle mid month raised last month's bill, because
the live statement at that point is the previous one. That is right when
the bill is genuinely unpaid, and wrong the rest of the time: most people
have paid it weeks ago, so what landed was a demand for money already
sent, dated in the past, arriving overdue on the day they set the feature
up.

Before raising a bill for the first time, payments credited to the card
since the statement date are counted against it, and it is skipped when
they cover it.

Credits only. Purchases made after the statement are not netted off,
because paying a bill settles it whatever you spend the next day; that
spending belongs to the next statement. A refund counts, as it does at
the bank.

This only decides whether the bill is raised at all. Once it exists its
amount stays what was billed, and part payments are recorded against it
in the usual way rather than quietly shrinking what it asks for.

Four tests around the day a cycle is set up: an unpaid bill from before
that day is still raised, a paid one is not, a short payment leaves it
standing at the billed amount, and spending after a full payment does not
revive it. Two of them fail without the check.


Claude-Session: https://claude.ai/code/session_016jkAcgzuuxTfBiAgMLWgC4

Co-authored-by: Claude <noreply@anthropic.com>