The nodes tool was missing from OWNER_ONLY_TOOL_NAME_FALLBACKS in
tool-policy.ts. applyOwnerOnlyToolPolicy() correctly removed gateway
and cron for non-owners but kept nodes, which internally issues
privileged gateway calls: node.pair.approve (operator.pairing) and
node.invoke (operator.write).
A non-owner sender could approve pending node pairings and invoke
arbitrary node commands, extending to system.run on paired nodes.
Add nodes to the fallback owner-only set. Non-owners no longer receive
the nodes tool after policy application; owners retain it.
Fixes GHSA-r26r-9hxr-r792
