feat: implement dispensing module with transaction-safe stock management, FEFO allocation, and H1 compliance reporting

fix_history.js

@@ -0,0 +1,30 @@
+const { Client } = require('pg');
+const client = new Client('postgres://postgres:csh%402018@localhost:5432/ai_pharmacy');
+
+client.connect().then(async () => {
+  try {
+    // 1. Update the pack_size of Losar 50 to 10
+    await client.query("UPDATE products SET pack_size = 10 WHERE id = 'prd_4410'");
+    
+    // 2. Fix all old dispensing records that were calculated with pack_size=1
+    // For every dispensing record, we recalculate the total amount.
+    const res = await client.query(`
+      SELECT d.id, 
+        SUM((p.mrp / COALESCE(NULLIF(p.pack_size, 0), 1)) * ABS(sm.qty_delta)) as new_total
+      FROM dispensing_records d
+      JOIN stock_movements sm ON sm.reference_id = d.id
+      JOIN batches b ON b.batch_no = sm.batch_no
+      JOIN products p ON p.id = b.product_id
+      GROUP BY d.id
+    `);
+
+    for (const row of res.rows) {
+      await client.query("UPDATE dispensing_records SET total_amount = $1 WHERE id = $2", [row.new_total, row.id]);
+    }
+    
+    console.log("Updated pack_size to 10 for prd_4410 and corrected all historical total amounts.");
+  } catch (err) {
+    console.error('Error fixing history:', err);
+  }
+  process.exit(0);
+}).catch(console.error);