Add catalog search on timeline header and fix Back to Timeline navigation.

Public GET /api/search over artists, movements, and paintings with a debounced header bar on the timeline; Back to Timeline resets zoom and gallery session.

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

scripts/migrate-search.js

@@ -0,0 +1,17 @@
+require('dotenv').config();
+const fs = require('fs');
+const path = require('path');
+const pool = require('../server/db');
+
+async function main() {
+  const sqlPath = path.join(__dirname, '../db/migrate-search.sql');
+  const sql = fs.readFileSync(sqlPath, 'utf8');
+  await pool.query(sql);
+  console.log('Catalog search indexes ready');
+  await pool.end();
+}
+
+main().catch((err) => {
+  console.error(err);
+  process.exit(1);
+});