Data::Shared scaling benchmark notes

Command for a fresh measurement against the installed backends:
  perl bench/scaling.pl

Controls: DS_BENCH_SIZES, DS_BENCH_WORKING_SET, DS_BENCH_ITERATIONS,
DS_BENCH_WORKERS.

The historical 2026-10-17 baseline/revised tables and derived comparisons
have been removed. The baseline required a saved pre-hardening source tree
that is not in this distribution, and neither sample identified an exact
source revision. Running the shipped script cannot reproduce that comparison.

Record the source revision, Perl/backend versions, commands and environment
with new output. Working-set timings use warm filesystem pages and include
instrumentation and scheduling. RSS includes the interpreter and allocator
history. Repeat measurements on an idle host for workload-specific conclusions.
