Spec PR 4. A front door onto the existing chapter parser: import a file, get a
chapter-delimited script in the editor.
Backend (new services/longform_import.py — pure, stdlib only, no new dep):
- chapterize_plaintext(text): inserts `# ` headings ahead of short standalone
chapter-title lines (Chapter/Part/Prologue/…); no-op if the text already has
H1s; long "Chapter …" sentences stay prose. ReDoS-safe (anchored, per-line).
- epub_to_chapter_script(bytes): parses EPUB (zipfile + ElementTree +
html.parser) in spine order → `# Title` + stripped body per document; skips
empty/nav pages; the heading becomes the chapter title (not narrated). Raises
ValueError on a malformed EPUB. ET.fromstring annotated `# nosec B314` (local
user file, no external-entity expansion).
- POST /audiobook/import (UploadFile) → {text, chapters}.
Frontend: an Import button (.txt/.md/.epub) that fills the script editor.
Tests: tests/test_longform_import.py (9) incl. an in-memory synthetic EPUB
(spine order, empty-doc skip, tag stripping, bad-zip). 64 backend + 326 frontend
green; build clean; en.json valid.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
