Three of the cases legitimately match nothing - they pin the case sensitivity
of the character search, the exact-match semantics of the numeric search, and
the "no data found" handling. They are worth keeping as regression coverage
but they make a poor demo video.
They now use an `itNegative` alias that resolves to `it.skip` when the spec is
run with `--env skipNegative=true`, so the walkthrough recording only ever
shows searches that return rows:
npx cypress run --browser electron \
--spec cypress/e2e/full-table-search.cy.ts --env skipNegative=true
CI runs the file with no env, so all nine cases still run there. The positive
half of the old case-sensitivity case is split out as its own test (3.1) so the
recording keeps it, and the "no data found" assertion is extracted into
assertNoData().