test: add freenet-test-network integration harness

[sanity]

Summary

• switch freenet-test-network dev dependency to the published 0.1.1 crate
• add reusable integration harness (manual diagnostics + connectivity tests)
• document how to run the suite locally as part of stacked PR validation

Testing

• cargo test --test test_network_integration
• cargo test --test diagnose_connectivity -- --ignored --exact

[sanity]

@claude please resolve conflicts

[claude]

Claude finished @sanity's task —— View job

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Merge Conflicts Resolved ✅

• Check for merge conflicts with base branch
• Identify conflicting files
• Apply changes to crates/core/src/node/p2p_impl.rs
• Apply changes to crates/core/src/operations/connect.rs
• Apply changes to crates/core/src/node/testing_impl.rs
• Verify changes match base commit
• Commit and push resolution

Summary

Successfully resolved merge conflicts by incorporating changes from the base branch (stack/connect-transport-rewrite). The conflicts were caused by commit d3318b5c which added proper shutdown handling for the initial join task.

Changes Applied

crates/core/src/node/p2p_impl.rs:

• Added JoinHandle import and field to track the background join task
• Modified run_node() to capture and store the join handle
• Added cleanup logic to abort the join task when the node shuts down

crates/core/src/operations/connect.rs:

• Changed initial_join_procedure() return type to Result<JoinHandle<()>, OpError>
• Captured and returned the spawn handle for the background task
• Added explanatory comment for courtesy_hint() logic

crates/core/src/node/testing_impl.rs:

• Updated run_node() to capture and abort the join task on completion

All changes match the base branch commit exactly. The PR branch is now up to date and ready for review.

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