v0.31.0

Changelog

• 2881d54 Merge pull request #217 from cozystack/fix/template-no-templates-guard
• d320cc6 fix(engine): require a template before rendering the chart
• cb340ab Merge pull request #131 from cozystack/feat/add-sysctl-etcd-defaults
• ca508b6 feat(cozystack): add DRBD-oriented sysctl and etcd backend defaults
• c3d7ace Merge pull request #212 from cozystack/fix/stdout-stderr-and-lookup-diagnostics
• bf869e4 Merge pull request #215 from cozystack/fix/lvm-loop-filter
• fbc207f test(engine): pin loop entry in lvm.conf global_filter contract
• 197fa71 fix(cozystack): exclude loop devices from LVM global_filter
• cc0239d docs(manual-test-plan): align retry section N.3 with actual iptables / cancellation semantics
• cf1008c fix(engine): route x509 SAN mismatch and other cert errors to TLSHandshake class
• cf45f7f fix(cli, engine): emit progress on stderr, enrich lookup error chain, retry transient failures