onebrc-probe(report): mark lane S as companion-PR-provided, fix reproduce loop

Addresses codex P2 (#638): on this T-only branch lane S is not defined, so
the report published results + a parity test for a lane users cannot run
here. Adds a 'Lane S provenance' note (S ships in the companion lane-S PR;
runnable lanes on this branch are a c r f t8 t) and drops `s` from the
reproduce loop with a note to re-add it once the companion PR merges. S rows
are kept in the ladder — the report's purpose is the full RAM-vs-trie
comparison and S is the fastest RAM-table method.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MLBnPuScZy6w9di2QEjsXM

Author: claude

crates/onebrc-probe/RESULTS_TRIE_VS_RAM.md

@@ -18,6 +18,13 @@
 > (native) per lane. Cardinality is ~400 stations (`gen.rs STATION_COUNT`);
 > results are for THIS workload, THIS machine, ONE corpus — see "Scope" at
 > the end.
+>
+> **Lane S provenance.** Lane S (SWAR) is NOT in this PR's diff — it ships in
+> the companion PR (`onebrc-probe: lane S`). Its rows below were measured with
+> that PR applied; on **this branch alone**, the runnable lanes are
+> `a c r f t8 t` and the `lane_s_agrees_with_lane_a` parity test lives in the
+> companion PR. S is kept in the ladder because the report's whole point is the
+> full RAM-table-vs-trie comparison, and S is the fastest RAM-table method.
 
 ## The methods (group-by-aggregate, min/max/sum/count per station)
 
@@ -148,7 +155,7 @@ count (10M). Not a claim about other CPUs, other cardinalities, or the full
 cd crates/onebrc-probe
 cargo build --release
 target/release/onebrc-probe gen /tmp/brc10m.txt 10000000 42   # if absent
-for lane in a c r f t8 t s; do
+for lane in a c r f t8 t; do   # add `s` once the companion lane-S PR is merged
   for i in $(seq 1 11); do target/release/onebrc-probe run /tmp/brc10m.txt $lane 4; done
 done   # take median + min/max/sd per lane, not best-of-N
 # native: RUSTFLAGS="-C target-cpu=native" cargo build --release --target-dir target-native