feat: add TLS certificate expiry check to HTTPS network monitors (#2401)

Co-authored-by: henrygd <hank@henrygd.me>

internal/migrations/1790193183_network_monitor_cert.go

@@ -0,0 +1,24 @@
+package migrations
+
+import (
+	"github.com/pocketbase/pocketbase/core"
+	m "github.com/pocketbase/pocketbase/migrations"
+)
+
+func init() {
+	m.Register(func(app core.App) error {
+		collection, err := app.FindCollectionByNameOrId("network_monitors")
+		if err != nil {
+			return err
+		}
+		collection.Fields.Add(&core.JSONField{Name: "certInfo"})
+		return app.Save(collection)
+	}, func(app core.App) error {
+		collection, err := app.FindCollectionByNameOrId("network_monitors")
+		if err != nil {
+			return err
+		}
+		collection.Fields.RemoveByName("certInfo")
+		return app.Save(collection)
+	})
+}