fc1700ea

By: ValentinHirschi <valentin.hirschi@gmail.com>

docs: rank n+2 limitations from the final review's findings 5, 6 and the layout outlier

Generic binary64 conditioning on light-like lanes (8 rational references
against the fast engine's 25), over-declared rank in the fast engine, and
the syn-n2-r2 width-1 code-placement slowdown: each documented with what
would fix it and why it is more than a local change.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Time to Start Worker time Duration Time to finish Idle
Config - - - - 39h54m37s
Eval - - - - -
Build - - - - -
Suite - - - - 39h54m37s