Extended from 3 to 6 seeds (added 24680/11111/99999) per Captain Bob's
request for a fuller campaign before moving on. amd64/11111/enabled,
riscv64/24680/enabled, riscv64/24680/disabled added. All 480/480 rows,
0 errors. Disabled-arm determinism (261063) holding across new seeds.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
