Sync reader draw ink to server for cross-device persistence

Previously reader ink was localStorage-only so it never followed the
user to a different browser or device.

- New reader_ink table (user_id, book_abbrev, chapter, strokes JSON)
- GET /api/reader/ink  — loads all pages for the signed-in user
- PUT /api/reader/ink/:book/:chapter — upserts one page
- On startup, client fetches server ink and merges it over localStorage
  (server wins so the most-recently saved version always wins)
- updateReaderPageInk debounces a PUT call 1 s after the last stroke,
  so rapid Apple Pencil strokes don't flood the server

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/index.js

@@ -11,6 +11,7 @@ import {
   getShareToken, setShareToken, clearShareToken, getProjectByShareToken,
   adminGetAllUsers, adminDeleteUser, adminGetAllProjects, adminGetProject, adminDeleteProject,
   setUserPassword, destroyAllSessionsForUser,
+  getAllReaderInk, setReaderInkPage,
 } from './db.js';
 import { SqliteSessionStore } from './sessionStore.js';
 import {
@@ -359,6 +360,34 @@ app.delete('/api/projects/:id', requireAuth, (req, res) => {
   }
 });
 
+// ---------------------------------------------------------------------------
+// Reader ink — cross-device draw annotations on Bible chapters
+// ---------------------------------------------------------------------------
+
+// GET /api/reader/ink — all saved ink pages for the current user
+app.get('/api/reader/ink', requireAuth, (req, res) => {
+  try {
+    res.json(getAllReaderInk(req.session.userId));
+  } catch (err) {
+    console.error('GET /api/reader/ink error:', err);
+    res.status(500).json({ error: 'Failed to load reader ink.' });
+  }
+});
+
+// PUT /api/reader/ink/:book/:chapter — save (upsert) one page's ink
+app.put('/api/reader/ink/:book/:chapter', requireAuth, (req, res) => {
+  try {
+    const { book, chapter } = req.params;
+    const { strokes } = req.body;
+    if (!Array.isArray(strokes)) return res.status(400).json({ error: 'strokes must be an array.' });
+    setReaderInkPage(req.session.userId, book, chapter, strokes);
+    res.json({ ok: true });
+  } catch (err) {
+    console.error('PUT /api/reader/ink error:', err);
+    res.status(500).json({ error: 'Failed to save reader ink.' });
+  }
+});
+
 // ---------------------------------------------------------------------------
 // Read-only share links
 // ---------------------------------------------------------------------------