feat: add Helm chart for Kubernetes deployment

Includes:
- Deployment with health checks and resource limits
- Service (ClusterIP by default)
- PersistentVolumeClaim for data storage
- Optional Ingress with TLS support
- Configurable via values.yaml

Usage: helm install taskplaner ./helm/taskplaner

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

helm/taskplaner/Chart.yaml

@@ -0,0 +1,14 @@
+apiVersion: v2
+name: taskplaner
+description: Personal task and notes management with image attachments
+type: application
+version: 0.1.0
+appVersion: "1.0.0"
+keywords:
+  - tasks
+  - notes
+  - productivity
+  - personal
+home: https://github.com/tricnet/taskplaner
+maintainers:
+  - name: TaskPlaner Team