Add queued email notifications for collaboration events

apps/server/internal/email/internal.go

@@ -0,0 +1,14 @@
+package email
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+)
+
+func randomToken(length int) (string, error) {
+	buf := make([]byte, length)
+	if _, err := rand.Read(buf); err != nil {
+		return "", err
+	}
+	return base64.RawURLEncoding.EncodeToString(buf), nil
+}