The slice changes no behaviour: the scanner still reads the old list. What it
adds is the ability to say how much of the estate is covered, and its acceptance
is a number already known by hand.
Both mistakes in this slice were caught by controls rather than by luck. The
counter-proof about tag ordering was itself wrong — name ordering loses v0.10.0,
not v0.8.0 — and the test failed until the reasoning was fixed. The first edit
to the compose file assumed the wrong indentation, and the assertion in front of
it stopped a half-applied change from being written.