[Alexander-Mitrofanov]

Summary

• seed numerical browser regressions from explicit test-only RNA inputs instead of the editable GUI examples
• keep the independent GUI example availability/JSON validation coverage
• update the prediction CSV assertion for the seed start/end coordinate defaults introduced by gui tweaks #305
• document the browser-test repair in the ChangeLog

Validation

• npm test --prefix gui — 29 tests passed
• python -m py_compile scripts/wasm/test-browser.py
• git diff --check
• Chromium with the current GUI and the newest locally available pre-CopomuS WASM bundle passed all prediction, evaluation, archive, cancellation, and session assertions; it reached the expected final mutation-only boundary where that older bundle lacks Pyodide

Fixes #310