Add model-bakeoff.md for the opencv5 build: the ten-knob DE tuning and where
each shipped config default comes from, the replay architecture, and the
flood-fill-on-learned-boundaries step change (62.6% -> 74.9% presence F1, LOO).
Rewrite index.md to lead with the learned scene-boundary result and point at
the current pages, with the July four-model bake-off moved to an Archive
section. Both pages build with no broken links.
dtourolle
7556c836da