The TUI /usage matrix sorted each quota window's account columns
independently by used fraction, so the positional `account N` labels
denoted different credentials on each row. An account exhausted on one
window but light on another (e.g. a Kimi Code account's 5h limit)
rendered its exhausted bar under a sibling that still had quota, making
the section `% free` and capacity numbers look wrong.
Order account columns once per provider (worst-first) and hold that
order stable across every window row.
Fixes#6067
LunarECL