Add Outline stage, parallel reading, offline saves, backup, sync-conflict handling and more

Study
- New Outline stage (hierarchical I./A./1. points, linked to chunks, in all exports);
  the chunk stage is now "Chunks"
- Home cards: passages shown as ranges, tags capped with "+N more"

Reader
- Side-by-side translations and a Compare tab per verse
- Typeface, line spacing, verse-number settings; text and column scale with the screen
- Highlights/bookmarks sheet with named colours (synced); BSB footnote spacing fix
- Cmd-K palette (passages, studies, notes, marks), keyboard shortcuts and "?" help

Flow and safety
- Toasts with Undo replace most confirm()/alert()
- Back/Forward move between pages
- Server refuses saves over a newer copy (409); keep-mine / use-other banner;
  opening a study no longer re-stamps it
- Latest chapter request wins when flipping quickly

Offline and data
- Save books, plan days or a whole BSB/NET for offline
- Service worker fixes: helloao /api/ URLs were skipped and responses cloned too late
- Settings: download/restore a full backup

Accessibility
- Sheets trap focus and close on Escape, skip link, focus ring, reduced motion,
  theme contrast raised to 4.5:1 (with a test)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/utils/docxExport.js

@@ -14,6 +14,7 @@ import {
   WidthType,
 } from 'docx';
 import { formatChunkReference, getChunkVerseEntries, htmlToPlainText } from './bibleUtils.jsx';
+import { flatten } from './outline.js';
 
 export function createParagraphsFromText(text) {
   return text
@@ -89,6 +90,22 @@ export async function buildStudyDocxBlob(project, chapterSummary) {
 
   const noBorder = { style: BorderStyle.NONE, size: 0, color: 'FFFFFF' };
 
+  // The outline comes first, indented by level like the page
+  if ((project.outline ?? []).length > 0) {
+    children.push(new Paragraph({ text: 'Outline', heading: HeadingLevel.HEADING_1, spacing: { before: 240, after: 160 } }));
+    flatten(project.outline).forEach(({ node, depth, label }) => {
+      children.push(new Paragraph({
+        indent: { left: 420 * depth, hanging: 420 },
+        spacing: { after: 80 },
+        children: [
+          new TextRun({ text: `${label}\t`, bold: true, color: DOCX_ACCENT }),
+          new TextRun({ text: (node.text ?? '').trim() || '(untitled)' }),
+          ...(node.ref ? [new TextRun({ text: `  (${node.ref})`, italics: true, color: '7A7060' })] : []),
+        ],
+      }));
+    });
+  }
+
   project.chapters.forEach((ch, chapterIndex) => {
     children.push(new Paragraph({
       text: `${ch.book} ${ch.chapter}`,