Bump k8s deployment image to 1.3.7 (#67)

Deployed and verified against the cluster: accountId "rockyl" + calendarId
"primary" now returns events with no warning.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: rockfordlhotka

k8s/deployment.yaml

@@ -28,7 +28,7 @@ spec:
         fsGroup: 1000
       containers:
         - name: calendar-mcp
-          image: docker.io/rockylhotka/calendar-mcp-http:1.3.6
+          image: docker.io/rockylhotka/calendar-mcp-http:1.3.7
           ports:
             - containerPort: 8080
               name: http