v0.3.1: verified numbers

No emulator or kernel changes. This release is about making the project's claims
checkable and the repository contributable.

Every published number re-measured

All five A100 throughput claims were re-measured from a clean clone and
reproduced at or above their published values. Two independent runs, on a
40 GB and an 80 GB A100, agreed to within 0.3%.

Envs	Previously published	Measured	Verdict
4,096	311,844	310,903	PASS
16,384	1,050,710	1,108,937	PASS
32,768	1,931,460	2,004,806	PASS
65,536	3,142,205	3,267,050	PASS
131,072	2,816,144	3,055,618	PASS

69/69 tests pass and all three falsifiability checks pass on the same run. Raw
output is committed at docs/data/verification-2026-09-01-a100.json.

Measured for the first time:

• Crossover at 8 environments, not the 32 and 64 the docs claimed. Both
  figures predated the 2026-07-29 optimization program.
• Device memory of ~195 KB per environment, 12.2 GiB at the 65,536-env
  peak. This confirms a "13 GB" figure the README had asserted with no
  measurement behind it.
• Linear scaling holds to ~8,192 envs, not ~2,048 as documented.

Reproduce it yourself

benchmarks/verify_claims.py reuses the functions in benchmarks/gpu_vs_cpu.py,
so the protocol matches the published tables exactly. It prints a
claimed-vs-measured table and exits non-zero if any claim, test, or check fails.
Run it directly, through notebooks/verify_claims.ipynb on Colab, or on a
rented GPU via the Colab CLI.

Corrected

Stale numbers were traced to the commit that wrote them and fixed:

• The nes-py comparison read 269x, computed against an intermediate build. It
  is ~1,370x.
• docs/design.md quoted throughput 6x below the README's own headline, with
  no indication it was historical.
• docs/benchmark-gpu-vs-cpu.md predates the entire optimization program and
  now carries a banner naming the specific corrections.
• KNOWN_ISSUES.md carried superseded A100 figures and claimed the C++ tests
  were not in CI; they have been since 394d090.
• MANIFEST.in omitted scripts/*.py, so sdists shipped without the build
  script the README tells users to run.
• A vendored doc cloned a repository name that no longer exists.

Contributing

• CONTRIBUTING.md: setup, the checks to run, and the bar for emulator and
  performance changes.
• Nine issues filed and labelled, each pointing at a specific file. The largest
  is mapper support beyond NROM (#5), which would take NeSLE from a Mario
  trainer to a general NES RL platform.
• docs/install.md splits the platform-specific build detail out of the README.
• Discussions enabled.