Controlled local ambiguous-save fixture

Requires Node.js 22. No packages, credentials, or external accounts.
Run: node ambiguous-save-fixture.mjs
Open http://127.0.0.1:3024/ in a browser. The server binds only to localhost.
A: Submit A once; read saved state A. Expect 503, one POST, one saved record.
B: Submit B; read state (zero records). Submit B again; read state. Expect two POSTs, one saved record.
C: Submit C twice; read state. Expect two POSTs, two saved records.
Stop with Ctrl-C. Restart the process for clean in-memory records. The event log appends on disk, so move or remove that file before comparing a fresh run.

Observed run: October 24, 2026; one fixed scripted ego-browser trial per case.
This is not a new n8n, Selenium, Cypress, or autonomous Claude Code run, and is not a reliability or performance benchmark. The server intentionally does not enforce key deduplication and does not model real timeouts or eventual consistency. All inputs and records are synthetic.
