Stage 18R Tier D verdict: dense/fused pool advantage reproduces on LF

Arm D re-derived from scratch on the normalized 5,966-chunk index with
the same Qwen3-Embedding-4B fp16 lane on the 3080 Ti (plain matrix
409.6s vs the original run's 409.6s; ctx 497.2s vs 507.9s).

Every non-maud cell of the fresh derivation reproduces the CRLF-era arm
table to four decimals across all six arms -- the only non-maud move is
cuad/ctx at -0.0027, caused by regenerated maud headers perturbing
global FTS statistics, not by the coordinate fix. maud is the only
column that moves, on every arm.

Fused maud pool R@48 0.8392 (ctx 0.6442) clears the frozen 0.50 OPEN bar
with no source dropping vs ctx: the verdict does not flip. Fused and
densectx keep their advantage nearly intact; dense-alone weakens by two
thirds on maud, because the lexical baseline it beat was the corrupted
one (lex maud recorded 0.3489, truly 0.6028).

Re-scoring the old sidecar gave maud 0.8625 / ALL 0.9584; re-deriving
gives 0.8392 / 0.9525. Re-scoring recovers offsets but not chunk
boundaries and keeps the old headers, so it flatters the arm by ~0.02 on
maud -- the measured size of "re-scoring is not enough".

Receipts (receipt store, not git): stage18r-dense-pools-lf.jsonl
8EC2FB7C, stage18r-fused-pools-lf.jsonl DCF8137F, combined LF header
sidecar C484C006, manifest stage18r-tierD-receipts.json 43759F0F.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H9ToHYJVDxfeJcJwdzrP2H