Run the harness wind-down in CI #343

Priority

Medium — should be addressed soon

User story / Problem statement

The harness has three suites: the happy path, the guards, and a wind-down on a throwaway vault (#261). CI runs the first two on every pull request. The wind-down suite only runs by hand, so a change that breaks a wind-down, or the vault build it needs, can reach feedback unnoticed.

As a maintainer, I want CI to run the wind-down suite on every pull request, so a broken wind-down fails the build.

Expected outcome

The build job runs the wind-down suite on the local network after the guards, and a failure fails the job.

Acceptance criteria

• The build job builds the vault with --features short_wind_down into target/short-wind-down
• The build job runs npm run test:wind-down -w scripts/harness with HARNESS_NETWORK=local, after the guards
• A failing wind-down fails the job and keeps the harness report

Technical notes

• The short_wind_down feature removes the seven-day wind-down minimum, so the suite runs in minutes. That Wasm is built only for this test and is never deployed.
• The suite passes locally (6 tests) on the current stack.