fix AutoRelay default zero value

[aojea]

No description provided.

[gemini-code-assist]

Code Review

This pull request adds AutoRelay configuration fields (AutoRelayMinInterval, AutoRelayBootDelay, and AutoRelayBackoff) to some NewSamNode instantiations in cmd/sam-node/main.go and updates an integration test. However, the reviewer noted that these fields are missing from other NewSamNode calls in the same file, specifically the post-enrollment and join command instances, which would cause them to fall back to zero values.

[aojea]

/gemini review again

[gemini-code-assist]

Code Review

This pull request configures auto-relay parameters (AutoRelayMinInterval, AutoRelayBootDelay, and AutoRelayBackoff) during mesh node initialization across different commands in cmd/sam-node/main.go, and updates an integration test parameter in tests/integration/failover_test.go. A review comment correctly identifies that these flags are not registered under the join command, which would cause them to default to zero values. It is recommended to pass safe default values directly for the join command initialization.