feat(ops): add k3s + ArgoCD GitOps pipeline

- Dockerfile: copy web/ and assets/ to runtime stage so ServeDir routes work
- .gitea/workflows/docker-build.yml: build/push image on master push, pin SHA
  tag back into deploy/kustomization.yaml so ArgoCD sees a real manifest change
- deploy/: Kustomize manifests — Namespace, PVC, Deployment (Recreate for
  SQLite), Service, Traefik Ingress at klondike.aleshym.co
- argocd/application.yaml: auto-sync Application watching deploy/ on Gitea

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

deploy/pvc.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: solitaire-db
+  namespace: solitaire
+spec:
+  accessModes:
+    - ReadWriteOnce
+  resources:
+    requests:
+      storage: 1Gi