The greedy score mixed incommensurate scales: cosine similarity bounded
to [-1, 1] against an absolute list index that grows with the pool. For
a candidate j positions later to be preferred at the default
diversity=0.5, its similarity advantage had to exceed j -- impossible for
the non-negative cosines real footage embeddings produce. diversify()
therefore returned the input order verbatim, placing exact-duplicate
clips in adjacent edit slots, the one thing its docstring promises to
prevent. The threshold where the knob started working also depended on
pool size (0.66 at 4 candidates, 0.95 at 11).
Normalize the position term to [0, 1] so both terms share a scale. The
documented endpoints hold exactly as before: diversity=0 returns input
order, diversity=1 picks the most mutually dissimilar. Enumerating the
position also drops the O(n^2) remaining.index() lookup per candidate.
Closes#392
7ad68f28ec