Capacity growth projection, per financial product with growth support.

Explains how the borrower's max borrowing capacity on a financial product grows over
usage "cycles": real past growth steps when the borrower is already in a cycle, and
1-2 illustrative future steps assuming on-time repayment. For growing, history ends
on the level in force — its last step is current_amount itself, and is the only
history step published without a date. Projected steps then start from that same
current_amount (the capacity deployed today), so the curve stays continuous.
Amounts are always computed server-side; internal configuration and income figures are
never returned, only the resulting curve (and whether it has plateaued, via
is_near_cap). A projected step can
also carry is_less_certain: even a step the curve keeps climbing toward can
need a human at deployment time, independently of is_near_cap. is_less_precise
flags the whole projection when it couldn't be based on the borrower's own income
figure and fell back to a generic cap instead.

progress states the usage criterion twice: as pct_to_next_threshold, and as the
amounts behind it — required_financing_amount is what the current cycle asks the
borrower to finance, remaining_financing_amount how much of it is left (0 once the
criterion is passed). The criterion is really a volume in amount x days, so both
amounts assume a loan running for the whole minimum cycle duration.

min_duration_days and pct_max_amount_to_use are the two cycle rules those figures
come from: finance at least pct_max_amount_to_use % of the capacity over a cycle
lasting at least min_duration_days days. They are configured per business financial
product, so read them from here rather than treating them as constants.

Returns one entry per eligible financial product. Only the receivable financing
product has cycle support today, so the list currently has at most one entry — an
empty list means the borrower has no such product yet.