fix: add migration to reset infrastructure thresholds from 5 to 100

## Changes
- Added migration 0004_fixInfrastructureThresholds that finds hardware
  monitors with threshold values of 5 (the old incorrect default) and
  updates them to 100 (effectively disabled)
- Runs automatically on server startup like other migrations

## Closes
Fixes #3327

server/src/db/migration/0004_fixInfrastructureThresholds.ts

@@ -0,0 +1,65 @@
+import { MonitorModel } from "../models/Monitor.js";
+import { logger } from "@/utils/logger.js";
+
+/**
+ * Fix infrastructure monitors that had thresholds incorrectly set to 5
+ * due to the old default value. Updates them to 100 (disabled).
+ */
+export async function fixInfrastructureThresholds(): Promise<void> {
+	const SERVICE_NAME = "Migration:FixInfrastructureThresholds";
+
+	try {
+		logger.info({ service: SERVICE_NAME, message: "Starting infrastructure threshold fix" });
+
+		const thresholdFields = [
+			"cpuAlertThreshold",
+			"memoryAlertThreshold",
+			"diskAlertThreshold",
+			"tempAlertThreshold",
+		];
+
+		// Find hardware monitors with any threshold set to 5
+		const filter = {
+			type: "hardware",
+			$or: thresholdFields.map((field) => ({ [field]: 5 })),
+		};
+
+		const monitors = await MonitorModel.find(filter);
+
+		if (monitors.length === 0) {
+			logger.info({ service: SERVICE_NAME, message: "No monitors with threshold value of 5 found" });
+			return;
+		}
+
+		logger.info({
+			service: SERVICE_NAME,
+			message: `Found ${monitors.length} monitors with threshold value of 5`,
+		});
+
+		let updatedCount = 0;
+
+		for (const monitor of monitors) {
+			const update: Record<string, number> = {};
+
+			for (const field of thresholdFields) {
+				if ((monitor as any)[field] === 5) {
+					update[field] = 100;
+				}
+			}
+
+			if (Object.keys(update).length > 0) {
+				await MonitorModel.updateOne({ _id: monitor._id }, { $set: update });
+				updatedCount++;
+			}
+		}
+
+		logger.info({
+			service: SERVICE_NAME,
+			message: `Fixed ${updatedCount} monitors — thresholds updated from 5 to 100`,
+		});
+	} catch (error) {
+		const errorMessage = error instanceof Error ? error.message : String(error);
+		logger.error({ service: SERVICE_NAME, message: `Error fixing thresholds: ${errorMessage}` });
+		throw error;
+	}
+}

server/src/db/migration/index.ts

@@ -1,6 +1,7 @@
 import { migrateStatusWindowThreshold } from "./0001_migrateStatusWindowThreshold.js";
 import { convertChecksToTimeSeries } from "./0002_convertChecksToTimeSeries.js";
 import { cleanupDuplicateMonitorStats } from "./0003_cleanupDuplicateMonitorStats.js";
+import { fixInfrastructureThresholds } from "./0004_fixInfrastructureThresholds.js";
 import MigrationModel from "../models/Migration.js";
 
 type MigrationEntry = {
@@ -12,6 +13,7 @@ const migrations: MigrationEntry[] = [
 	{ name: "0001_migrateStatusWindowThreshold", execute: migrateStatusWindowThreshold },
 	{ name: "0002_convertChecksToTimeSeries", execute: convertChecksToTimeSeries },
 	{ name: "0003_cleanupDuplicateMonitorStats", execute: cleanupDuplicateMonitorStats },
+	{ name: "0004_fixInfrastructureThresholds", execute: fixInfrastructureThresholds },
 ];
 
 const runMigrations = async (logger?: { info: Function; error: Function }) => {