Task 4's implementer found that SB195 does not surface for a
recipe query spanning only 2011-2012. .build_series_break_refs() matches
break_year BETWEEN min(years) AND max(years), and SB195's break_year is 2002.
That is correct behaviour rather than a gap: a series lying entirely after the
book -> market change sits on one consistent basis, so disclosing a break it
never crosses would be noise. .build_corpus_break_refs() applies the same rule
deliberately.
The spec's caveat table overclaimed by omitting the span condition. Corrected.