Highlight translation differences, first-draft snapshot, verse notes, paste check

- Compare translations can highlight the words that differ from the first
  translation (toggle remembered).
- A copy of your notes is kept the first time commentary is shown; "First draft,
  before commentary" under More shows what changed since. Saving it doesn't
  count as editing the chunk.
- Notes on single verses: a pencil next to each verse in Study, and a note line
  under each verse in Compare. They merge per verse across devices.
- Pasting 15+ words into a note asks "Is this from AI?"; "I wrote it" counts the
  words as yours again.

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

src/utils/compareTranslations.js

@@ -1,5 +1,6 @@
 // Comparing translations of one chunk: which chapter(s) and verses to fetch, and the verses lined up by number.
 import { getChunkVerseEntries } from './bibleUtils.jsx';
+import { diffVerses } from './textDiff.js';
 
 // -> [{ bookAbbrev, book, chapter, from, to }]: one entry per chapter the chunk covers (two when it spills over).
 export function translationSpans(project, chapterIndex, chunk) {
@@ -23,8 +24,33 @@ export function alignVerses(spans, byTranslation) {
       for (const [id, chapters] of Object.entries(byTranslation)) {
         texts[id] = chapters?.[`${span.book}|${span.chapter}`]?.find((v) => v.number === n)?.text ?? null;
       }
-      rows.push({ key: `${span.book}${span.chapter}:${n}`, label: spans.length > 1 ? `${span.chapter}:${n}` : String(n), texts });
+      rows.push({ key: `${span.book}${span.chapter}:${n}`, noteKey: `${span.chapter}:${n}`, label: spans.length > 1 ? `${span.chapter}:${n}` : String(n), texts });
     }
   }
   return rows;
 }
+
+// For one verse in several translations: which words in each text the others lack, measured against the first
+// translation (and the first against the second). -> { BSB: [{ start, end }], NET: [...] }
+export function differencesFor(texts, ids) {
+  const out = Object.fromEntries(ids.map((id) => [id, []]));
+  const present = ids.filter((id) => texts[id]);
+  if (present.length < 2) return out;
+  const [base, ...rest] = present;
+  out[base] = diffVerses(texts[base], texts[rest[0]]).a;
+  for (const id of rest) out[id] = diffVerses(texts[base], texts[id]).b;
+  return out;
+}
+
+// Cuts a text at the ranges -> [{ text, mark }] so a view can wrap the marked parts.
+export function markRanges(text, ranges) {
+  const parts = [];
+  let at = 0;
+  for (const r of [...(ranges ?? [])].sort((a, b) => a.start - b.start)) {
+    if (r.start > at) parts.push({ text: text.slice(at, r.start), mark: false });
+    parts.push({ text: text.slice(r.start, r.end), mark: true });
+    at = r.end;
+  }
+  if (at < text.length) parts.push({ text: text.slice(at), mark: false });
+  return parts;
+}

src/utils/compareTranslations.test.js

@@ -27,3 +27,19 @@ test('verses are lined up by number, with null where a translation lacks one', (
   expect(rows[0].texts).toEqual({ BSB: 'a', NET: 'c' });
   expect(rows[1].texts).toEqual({ BSB: 'b', NET: null });
 });
+
+import { differencesFor, markRanges } from './compareTranslations.js';
+
+test('differences are the words a translation has that the first one lacks', () => {
+  const d = differencesFor({ BSB: 'For God so loved the world', NET: 'For this is the way God loved the world', ESV: 'For God so loved the world' }, ['BSB', 'NET', 'ESV']);
+  expect(d.ESV).toEqual([]); // same words as the first
+  const text = 'For this is the way God loved the world';
+  expect(markRanges(text, d.NET).filter((p) => p.mark).map((p) => p.text.trim()).join(' ')).toContain('this is the way');
+  expect(differencesFor({ BSB: 'a b', NET: null }, ['BSB', 'NET']).BSB).toEqual([]); // nothing to compare against
+});
+
+test('markRanges splits a text into plain and marked pieces that rejoin to the original', () => {
+  const parts = markRanges('one two three four', [{ start: 4, end: 7 }, { start: 14, end: 18 }]);
+  expect(parts.map((p) => p.text).join('')).toBe('one two three four');
+  expect(parts.filter((p) => p.mark).map((p) => p.text)).toEqual(['two', 'four']);
+});

src/utils/mergeStudies.js

@@ -37,6 +37,10 @@ export function mergeChunk(mine, theirs) {
   LIST_FIELDS.forEach((f) => { out[f] = union(newer[f], older[f]); });
   // Pastes follow their text: keep the union per field so merged notes still show what was pasted.
   out.aiPastes = Object.fromEntries(['observation', 'interpretation', 'application'].map((f) => [f, union(newer.aiPastes?.[f], older.aiPastes?.[f])]));
+  // Verse notes are kept per verse (the newer wording wins, an older different one is appended); the earliest first draft is kept.
+  const noteKeys = new Set([...Object.keys(newer.verseNotes ?? {}), ...Object.keys(older.verseNotes ?? {})]);
+  out.verseNotes = Object.fromEntries([...noteKeys].map((k) => [k, mergeText(newer.verseNotes?.[k], older.verseNotes?.[k])]));
+  out.firstDraft = [newer.firstDraft, older.firstDraft].filter(Boolean).sort((a, b) => a.at - b.at)[0];
   out.followUps = mergeById(newer.followUps, older.followUps);
   out.recalls = union(newer.recalls, older.recalls);
   out.editedAt = Math.max(mine.editedAt ?? 0, theirs.editedAt ?? 0) || undefined;

src/utils/ownWork.js

@@ -51,3 +51,13 @@ export function chunksNeedingWork(chunks) {
 // Commentary and study aids stay folded away until you've written this much of your own Observe notes.
 export const OBSERVE_FIRST_MIN = 15;
 export const observeFirstDone = (chunk) => ownWords(chunk, 'observation') >= OBSERVE_FIRST_MIN;
+
+// "No, I wrote it": take one remembered paste back out, so those words count as your own again.
+export function withoutPaste(chunk, field, pasted) {
+  const text = (pasted ?? '').trim();
+  const all = chunk?.aiPastes ?? {};
+  const list = [...(all[field] ?? [])];
+  const at = list.lastIndexOf(text);
+  if (at >= 0) list.splice(at, 1);
+  return { ...all, [field]: list };
+}

src/utils/ownWork.test.js

@@ -56,3 +56,14 @@ test('merging two copies keeps the pastes from both', () => {
   const b = { id: 'x', observation: 'b', editedAt: 1, aiPastes: { observation: ['p2'] } };
   expect(mergeChunk(a, b).chunk.aiPastes.observation).toEqual(['p1', 'p2']);
 });
+
+import { withoutPaste } from './ownWork.js';
+
+test('"No, I wrote it" takes one paste back out so the words count as yours again', () => {
+  const pasted = text(30);
+  const chunk = { observation: pasted, aiPastes: { observation: [pasted, 'other'] } };
+  const after = { ...chunk, aiPastes: withoutPaste(chunk, 'observation', `  ${pasted} `) };
+  expect(after.aiPastes.observation).toEqual(['other']);
+  expect(ownWords(after, 'observation')).toBe(30);
+  expect(withoutPaste({}, 'observation', 'x')).toEqual({ observation: [] });
+});