Add public curator notes and U-shaped hall wall hang.

Paintings get editable curator notes with brass plates in the 3D hall, and visit order now uses the far/end wall between left and right.

Co-authored-by: Cursor <cursoragent@cursor.com>

server/index.js

@@ -836,6 +836,45 @@ app.patch('/api/paintings/:id/checkup-flags', requireCurator, async (req, res) =
   }
 });
 
+// Update public curator notes on a painting
+app.patch('/api/paintings/:id/curator-notes', requireCurator, async (req, res) => {
+  try {
+    const paintingId = parseInt(req.params.id, 10);
+    if (!Number.isFinite(paintingId)) {
+      return res.status(400).json({ error: 'Invalid painting id' });
+    }
+
+    if (typeof req.body?.curatorNotes !== 'string') {
+      return res.status(400).json({ error: 'curatorNotes must be a string' });
+    }
+    const curatorNotes = req.body.curatorNotes.trim();
+
+    const result = await pool.query(
+      `UPDATE paintings SET curator_notes = $2
+       WHERE id = $1
+       RETURNING curator_notes`,
+      [paintingId, curatorNotes]
+    );
+    if (result.rows.length === 0) {
+      return res.status(404).json({ error: 'Painting not found' });
+    }
+
+    res.json({ curatorNotes: result.rows[0].curator_notes ?? '' });
+
+    await logCuratorAction({
+      userId: req.curatorUser.id,
+      action: 'painting.update_curator_notes',
+      resourceType: 'painting',
+      resourceId: paintingId,
+      details: { length: curatorNotes.length },
+      req,
+    });
+  } catch (err) {
+    console.error('Curator notes update error:', err.message);
+    res.status(500).json({ error: 'Failed to update curator notes' });
+  }
+});
+
 // Painting detail with influences
 app.get('/api/paintings/:id', async (req, res) => {
   try {