feat: add core backend modules, inventory services, and patch scripts for AI Pharmacy API

test_cat.js

@@ -0,0 +1,21 @@
+const { pool } = require('./src/db/pool');
+
+async function test() {
+  const query = `
+      SELECT 
+        p.id as product_id, 
+        p.brand_name, 
+        d.generic_name, 
+        (SELECT COALESCE(SUM(qty_on_hand), 0) FROM batches WHERE product_id = p.id AND expiry > CURRENT_DATE AND tenant_id = $2) as total_stock
+      FROM products p
+      JOIN drugs d ON p.drug_id = d.id
+      WHERE p.tenant_id = $2 OR EXISTS (SELECT 1 FROM batches WHERE product_id = p.id AND tenant_id = $2) OR p.tenant_id IS NULL
+      ORDER BY p.brand_name ASC
+      LIMIT $1
+    `;
+  const { rows } = await pool.query(query, [50, 'act_admin']);
+  console.log(rows);
+  process.exit();
+}
+
+test();