feat: Add stale process monitor, users route, landing page, archive old scripts

- Add backend stale process monitoring API (/api/stale-processes)
- Add users management route
- Add frontend landing page and stale process monitor UI on /scraper-tools
- Move old development scripts to backend/archive/
- Update frontend build with new features

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

backend/archive/check-products-schema.ts

@@ -0,0 +1,47 @@
+import { pool } from './src/db/migrate.js';
+
+async function main() {
+  const result = await pool.query(`
+    SELECT column_name, data_type, is_nullable
+    FROM information_schema.columns
+    WHERE table_name = 'products'
+    ORDER BY ordinal_position;
+  `);
+
+  console.log('Products table columns:');
+  result.rows.forEach(row => {
+    console.log(`  ${row.column_name}: ${row.data_type} (${row.is_nullable === 'YES' ? 'nullable' : 'NOT NULL'})`);
+  });
+
+  const constraints = await pool.query(`
+    SELECT constraint_name, constraint_type
+    FROM information_schema.table_constraints
+    WHERE table_name = 'products';
+  `);
+
+  console.log('\nProducts table constraints:');
+  constraints.rows.forEach(row => {
+    console.log(`  ${row.constraint_name}: ${row.constraint_type}`);
+  });
+
+  // Get unique constraints details
+  const uniqueConstraints = await pool.query(`
+    SELECT
+      tc.constraint_name,
+      kcu.column_name
+    FROM information_schema.table_constraints tc
+    JOIN information_schema.key_column_usage kcu
+      ON tc.constraint_name = kcu.constraint_name
+    WHERE tc.table_name = 'products'
+      AND tc.constraint_type IN ('PRIMARY KEY', 'UNIQUE');
+  `);
+
+  console.log('\nUnique/Primary key constraints:');
+  uniqueConstraints.rows.forEach(row => {
+    console.log(`  ${row.constraint_name}: ${row.column_name}`);
+  });
+
+  await pool.end();
+}
+
+main().catch(console.error);