Add own-work tracking, Claude hand-off check, and weekly recall

- Long pastes into Observe/Interpret/Apply are tagged as pasted; notes show
  Mine / N pasted and an own-words share. Pastes follow text through merges.
- The "-> Claude" buttons on the Script stage ask first when a chunk lacks
  enough of the user's own (non-pasted) words.
- Weekly recall card on Home: write a passage from memory, compare with notes,
  self-rate; recalls are saved on the chunk and synced.
- Recall history on Home with an eight-week strip and the full list.

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

src/utils/mergeStudies.js

@@ -29,6 +29,9 @@ export function mergeChunk(mine, theirs) {
   const out = { ...older, ...newer };
   TEXT_FIELDS.forEach((f) => { out[f] = mergeText(newer[f], older[f]); });
   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])]));
+  out.recalls = union(newer.recalls, older.recalls);
   out.editedAt = Math.max(mine.editedAt ?? 0, theirs.editedAt ?? 0) || undefined;
   return { chunk: out, changed: !same(out, mine) };
 }