No CI: every test and check is run by hand

[isenbek]

tinymachines/halfphi has GitHub Actions; this repository has none. Everything
below is currently run by hand and therefore only when someone remembers.

What CI would need to run

cargo test --workspace          # 83 tests
cargo clippy --workspace --all-targets
node tools/check-programs.mjs   # the programs assemble and round-trip

The awkward parts, which are why this has not happened

• The golden test needs a 5 MB oracle generated by node tools/golden-trace/ gen.js --steps 3000. Without it the test SKIPS. V6502_REQUIRE_GOLDEN=1 makes
  its absence a failure, which is what CI should set — a skip that looks like a
  pass is worse than a failure.
• The web harnesses need a browser. There are 23 of them and they are the
  only test route the front end has. They need a static server plus headless
  Chromium, and on this machine google-chrome headless hangs on any page load
  (v149) while snap chromium works — so the invocation is not portable.
• The die data is a submodule, so checkout needs submodules: recursive.

Suggested shape

Start with the Rust and the program check, which need no browser and would have
caught a real failure this project shipped (a doctest broken by a rename). Add
the web harnesses as a second job once the browser invocation is pinned down.