[tmpnet] Ensure Node has a reference to Network

[maru-ava]

PR Chain: tmpnet+kube

This PR chain enables tmpnet to deploy temporary networks to Kubernetes. Early PRs refactor tmpnet to support the addition in #3615 of a new tmpnet node runtime for kube.

• [tmpnet] s/Network.ChainConfigs/Network.PrimaryChainConfigs/ #3854
• [tmpnet] Provide genesis, subnet and chain config via content flags #3857
• >>>>>> [tmpnet] Ensure Node has a reference to Network #3870 <<<<<<
• [tmpnet] Switch back to using maps for subnet config #3877
• [tmpnet] Refactor runtime configuration in preparation for kube #3867
• [tmpnet] Unify start network flag usage between e2e and tmpnetctl #3871
• [tmpnet] Avoid serializing the node data directory #3881
• [tmpnet] Rename NodeProcess to ProcessRuntime #3890
• [tmpnet] Switch FlagsMap from map[string]any to map[string]string #3884
• [tmpnet] Ensure tmpnet methods always have a logger #3893
• [tmpnet] Ensure all node runtime methods accept a context #3894
• [tmpnet] Move WaitForHealthy from a function to a tmpnet.Node method #3896
• [tmpnet] Delegate writing of the flag file to the runtime #3897
• [tmpnet] Move monitoring label handling to node #3898
• [tmpnet] Enable runtime-specific restart behavior #3882
• [tmpnet] Enable deployment to kube #3615
• [tmpnet] Enable monitoring of local kind cluster #3794

Why this should be merged

Previously tmpnet.Node was serialized with a subset of tmpnet.Network fields like UUID and Owner. Intead, tmpnet.Node gets a reference to its owning tmpnet.Network on read or start to ensure it has full access to all network details.

How this was tested

CI

Need to be documented in RELEASES.md?

N/A

[Copilot]

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