v0.53.0

0.53.0 (2026-09-02)

Added

• Core: DocxEditor.ReplaceText can match a regular expression, not just literal keys.
  A new overload takes a Regex and a replacement template, with a Stream form beside it, and
  applies across the body, headers, footers, footnotes and endnotes exactly as the literal overload
  does. Anything whose shape is known but whose text is not - dates, reference numbers, whitespace -
  now has an entry point.

  The replacement is a TEMPLATE, not a literal. $1 and friends expand to captured groups the
  way Regex.Replace expands them, so a literal $ must be written $$.

  The pattern must carry a match timeout, and one without is refused with an ArgumentException
  rather than accepted. A catastrophically backtracking expression has no upper bound on its running
  time, and a hang is worse than a failure because the caller cannot catch it. Construct it as
  new Regex(text, RegexOptions.None, TimeSpan.FromSeconds(1)).

  Formatting behaves exactly as it already did for literal keys: where a match spans several
  runs, the replacement is written into the run holding its first character and inherits that run's
  formatting. Zero-width matches are skipped, because one consumes no characters.

  Nothing existing changed. The literal overload is untouched, and both now share one
  implementation of the run-splicing step rather than two that could drift.

• Extensions: IPdfEditor mirrors ExtractWords and ExtractImages from core 0.52.0, with
  their Stream forms - four members, so the PDF word-position and image extraction added last
  release is now reachable through dependency injection.

  Two things a caller gets wrong without being told, and which the interface documentation now
  states: coordinates are measured from the page's bottom-left, so a word near the top of A4 has
  a Bottom near 842 rather than near 0; and PdfImage.Png is null when the pixels could not be
  re-encoded, which is a normal outcome rather than an error.