Add Helm chart, replace flux/ variable-substitution templates

Introduces chart/ with deployment, service, and PVC templates driven
by Helm values instead of Kustomize variable substitution. Removes
the flux/ directory which is superseded by the chart.

Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

chart/templates/service.yaml

@@ -0,0 +1,14 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: {{ include "antigravity.fullname" . }}
+  labels:
+    {{- include "antigravity.labels" . | nindent 4 }}
+spec:
+  ports:
+    - port: 5800
+      name: vnc-web
+      protocol: TCP
+      targetPort: vnc-web
+  selector:
+    {{- include "antigravity.labels" . | nindent 4 }}