fix: correct walkthrough field names in demo seed

backend/prisma/seed-demo.js

@@ -149,20 +149,17 @@ async function main() {
     console.log('\n📝 Creating Walkthrough History...');
     for (let d = 0; d < 30; d++) {
         const user = userList[Math.floor(Math.random() * userList.length)];
+        const startTime = daysAgo(d);
+        const endTime = new Date(startTime);
+        endTime.setMinutes(endTime.getMinutes() + 30 + Math.floor(Math.random() * 30));
+
         const walkthrough = await prisma.dailyWalkthrough.create({
             data: {
-                userId: user.id,
+                completedBy: user.id,
                 status: 'COMPLETED',
-                startedAt: daysAgo(d),
-                completedAt: daysAgo(d),
-                notes: d === 0 ? null : [
-                    'All rooms looking good',
-                    'Found spider mites in Flower A, treated with Pyganic',
-                    'VPD running high, adjusted humidity',
-                    'Reservoir topped off',
-                    'Noticed some cal-mag deficiency in veg',
-                    null
-                ][Math.floor(Math.random() * 6)]
+                date: daysAgo(d),
+                startTime,
+                endTime
             }
         });