fix(migrations): add created_at/updated_at to archer_tickets if missing

Production instances where the table was created before these columns
were added to the schema will see 500 errors on all /api/archer-tickets
endpoints. This migration safely checks PRAGMA table_info before each
ALTER TABLE so it is idempotent and safe to run multiple times.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/migrations/add_archer_tickets_timestamps.js

@@ -0,0 +1,56 @@
+// Migration: Add created_at / updated_at columns to archer_tickets
+//
+// SQLite does not support ALTER TABLE ADD COLUMN IF NOT EXISTS, so we check
+// PRAGMA table_info first and only add the column when it is absent.
+//
+// Run on any instance where archer_tickets was created before these columns
+// were added to the schema (symptoms: every /api/archer-tickets call → 500).
+//
+// Usage: node backend/migrations/add_archer_tickets_timestamps.js
+
+const sqlite3 = require('sqlite3').verbose();
+const path    = require('path');
+
+const dbPath = path.join(__dirname, '..', 'cve_database.db');
+const db     = new sqlite3.Database(dbPath);
+
+console.log('Starting archer_tickets timestamp migration...');
+
+db.all('PRAGMA table_info(archer_tickets)', [], (err, columns) => {
+    if (err) {
+        console.error('Error reading table info:', err);
+        return db.close();
+    }
+
+    const names = columns.map(c => c.name);
+
+    db.serialize(() => {
+        if (!names.includes('created_at')) {
+            db.run(
+                `ALTER TABLE archer_tickets ADD COLUMN created_at DATETIME DEFAULT CURRENT_TIMESTAMP`,
+                (err) => {
+                    if (err) console.error('Error adding created_at:', err);
+                    else console.log('✓ created_at column added');
+                }
+            );
+        } else {
+            console.log('✓ created_at already exists — skipping');
+        }
+
+        if (!names.includes('updated_at')) {
+            db.run(
+                `ALTER TABLE archer_tickets ADD COLUMN updated_at DATETIME DEFAULT CURRENT_TIMESTAMP`,
+                (err) => {
+                    if (err) console.error('Error adding updated_at:', err);
+                    else console.log('✓ updated_at column added');
+                }
+            );
+        } else {
+            console.log('✓ updated_at already exists — skipping');
+        }
+    });
+
+    db.close(() => {
+        console.log('Migration complete. Restart the backend server.');
+    });
+});