How do I import a manuscript that has front matter (a preface, an introduction, a dedication) without it becoming Chapter 1?

Since v1.8.4 the import preview gives every detected section a destination selector. Sections recognized as front or back matter are pre-labeled from their titles — an "Introduction" page is suggested as Introduction, a "Letter to Reader" as Preface, a "Dedication" as Dedication, and so on — and you can change any of them: Chapter, Preface, Introduction, Dedication, Prologue, Acknowledgments, Epilogue, Glossary, or "Don't import". Sections you send to a matter destination land in the book's dedicated matter pages: they're editable in the book workspace (the pencil icon in the "Include in book" list), they export in the correct front/back-matter order, and they are

NEVER counted as chapters — so your chapter numbering and table of contents stay exactly as written. No special heading tricks needed.