Preserve audiobook pagination when saving to Rehearser (v1.9.2)

audiobookScopeText now records PDF page boundaries as character offsets in the
scope text; audiobookBuildScript realigns each segment against the source and
emits \f page-break markers at the nearest boundary. Saved/opened cast scripts
keep the book's pagination instead of collapsing to one flow.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

CHANGELOG.md

@@ -9,6 +9,13 @@ Follows [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) · versioned wi
 
 ---
 
+## [1.9.2] — 2026-06-26
+
+### Fixed
+- **Audiobook casting — pagination preserved on save**: saving (or opening) a cast audiobook as a Script Rehearsal now keeps the book's **page breaks**. Read-aloud page boundaries are tracked through casting and re-emitted as `\f` markers at the nearest segment boundary, so the Rehearser paginates the saved script to match the source PDF instead of producing one continuous flow.
+
+---
+
 ## [1.9.1] — 2026-06-26
 
 ### Fixed

VERSION

@@ -1 +1 @@
-1.9.1
+1.9.2

static/js/audiobook.js

@@ -97,10 +97,33 @@ function audiobookLlmModel() { return $('reh-llm-model')?.value || ''; }
 function audiobookLang()     { return $('reh-design-lang')?.value || ''; }
 
 // Gather the plain text of the current reader scope (selection > page range > all).
+// Also records PDF page boundaries as character offsets in the returned text
+// (_audiobook.pageMarks) so saving to the Rehearser can reconstruct page breaks.
 function audiobookScopeText() {
+  _audiobook.pageMarks = [];
   if (typeof readerScopeIndices !== 'function' || !readerState?.sentences?.length) return '';
-  const raw = readerScopeIndices().map(i => readerState.sentences[i].text).join(' ').replace(/\s+/g, ' ').trim();
+  const idxs = readerScopeIndices();
-  return audiobookDehyphenate(raw);   // mend PDF line-break hyphenation for clean speech + tag matching
+  const anchors = [];                 // {page, anchor} — first sentence of each new page
+  let lastPage = null;
+  for (const i of idxs) {
+    const u = readerState.sentences[i];
+    const pg = u?.words?.[0]?.page;
+    if (pg != null && pg !== lastPage) {
+      anchors.push({ page: pg, anchor: (u.text || '').trim().slice(0, 40) });
+      lastPage = pg;
+    }
+  }
+  const raw = idxs.map(i => readerState.sentences[i].text).join(' ').replace(/\s+/g, ' ').trim();
+  const text = audiobookDehyphenate(raw);   // mend PDF line-break hyphenation for clean speech + tag matching
+  // Locate each page anchor in the final text → page-break offsets.
+  let from = 0;
+  for (const a of anchors) {
+    const probe = audiobookDehyphenate(a.anchor).slice(0, 24);
+    if (!probe) continue;
+    const pos = text.indexOf(probe, from);
+    if (pos >= 0) { _audiobook.pageMarks.push({ offset: pos, page: a.page }); from = pos; }
+  }
+  return text;
 }
 
 // ── Progress overlay ─────────────────────────────────────────────────────────
@@ -1246,11 +1269,32 @@ function audiobookApplyPreviewAndOpen() {
 
 // Build a rehearser script (CAPS speaker + line; narration as plain paragraphs)
 // and a parallel list of per-dialogue-line emotions (same order as dialog lines).
+// Inserts \f page-break markers at the segment boundary nearest each source PDF
+// page start (so saved/opened scripts keep the book's pagination). Page positions
+// are realigned per-segment against the source text to avoid cumulative drift.
 function audiobookBuildScript(segments) {
   let script = '';
   const emotions = [];
+  const marks = _audiobook.pageMarks || [];
+  const src = _audiobook.lastText || '';
+  let markIdx = 0, searchPos = 0;
+  // The first page mark sits at the start of the document — no leading break.
+  if (marks.length && marks[0].offset <= 2) markIdx = 1;
+
   for (const s of segments) {
     const t = (s.text || '').trim(); if (!t) continue;
+    // Where does this segment sit in the source text? (verbatim narration matches
+    // exactly; dialogue text — quotes stripped — still occurs in the source.)
+    if (src && markIdx < marks.length) {
+      const probe = t.slice(0, 24);
+      const at = probe ? src.indexOf(probe, searchPos) : -1;
+      const pos = at >= 0 ? at : searchPos;
+      if (at >= 0) searchPos = at + probe.length;
+      while (markIdx < marks.length && pos >= marks[markIdx].offset) {
+        if (script.trim()) script += '\n\f\n';   // page break before this segment
+        markIdx++;
+      }
+    }
     const isDialogue = s.type === 'dialogue' && s.speaker && s.speaker.toLowerCase() !== 'narrator';
     if (isDialogue) {
       script += '\n' + s.speaker.toUpperCase() + '\n' + t + '\n';