The typography-folded fallback in _substring_matches rejected a needle only when
it was quotes/dashes at the ends (needle.strip("'-")), so old_text="\u201c \u2014"
(curly quote, space, em dash) folded to "' -" and matched any entry containing
`" -`, deleting it via single or batch remove. The fallback now requires at least
one alphanumeric character; exact-entry and byte-substring priority are unchanged.
Tests: the PR's four new tests are folded into two invariants (layout/typography
match + punctuation-only rejection; self-correcting failure copy + #90468 alias).
b9013584b2