Paper-style cache-aware MoE selection (arXiv:2412.00099 max-rank):
keep true top-J always; fill remaining K slots preferring experts already
resident in pin∪LRU within top-M. Default OFF so stock full top-K is
unchanged.
Env: CACHE_ROUTE, ROUTE_J/M/P/ALPHA, ROUTE_AGREE (auto-on with CACHE_ROUTE).
Telemetry: swap%/route_swaps/route_slots, route_agree, route_kl on footer
and serve STAT. Complementary to PILOT (prefetch vs selection change).
Routing-only PR for clean A/B vs PILOT / #119; no CUDA/fuse stack.
See docs/CACHE_ROUTE.md. Closes nothing; for #161 discussion.
Co-authored-by: Vincent Marquez <vincentmarquez405@gmail.com>
Marquez