chore(freshrss): remove TrueCharts HelmRelease

[luckycold]

Summary

• remove the suspended HelmRelease from clusters/main/kubernetes/apps/freshrss/app and delete helm-release.yaml
• keep existing plain Deployment, Service, Ingress, PVC, and VolSync resources and names intact
• add explicit shared runtime emptyDir volumes and mounts (shared, tmp, devshm, varlogs, varrun) to both containers to preserve live pod behavior

Compatibility

• PVC name remains freshrss-config with storageClass longhorn
• VolSync wiring remains unchanged: ReplicationSource freshrss-config-minio still points to sourcePVC freshrss-config and repository secret freshrss-config-volsync-minio
• service and ingress names/hosts/classes remain unchanged: freshrss and freshrss-codeserver, rss.1al.cc external, rss-cs.1al.cc internal, cert-manager issuer domain-0-le-prod

Validation

• kubectl kustomize clusters/main/kubernetes/apps/freshrss/app (pass)
• kubectl kustomize clusters/main/kubernetes (pass)
• flux diff ks freshrss --path clusters/main/kubernetes/apps/freshrss/app (only expected deletion: HelmRelease/freshrss/freshrss)
• kubectl apply --server-side --dry-run=server -k clusters/main/kubernetes/apps/freshrss/app (rendered; expected SSA field-manager conflicts on existing ingresses; SOPS secret typed-patch schema warning)