test(node): improve unit test coverage for node module

[sanity]

Problem

The crates/core/src/node module had low unit test coverage, particularly mod.rs at 3.34% and network_bridge.rs at 80.37%. This makes it harder to catch regressions and understand expected behavior of core node components.

This Solution

Add comprehensive unit tests focusing on testable pure logic without requiring complex network mocking:

Coverage Improvements

File	Before	After	Improvement
node/mod.rs	3.34%	23.19%	+19.85%
node/network_bridge.rs	80.37%	89.05%	+8.68%
node/network_bridge/priority_select.rs	60.45%	76.87%	+16.42%

Tests Added

node/mod.rs:

• PeerId tests (equality based on address, ordering, hashing, serialization, display)
• InitPeerNode construction tests
• is_operation_completed function with various error conditions
• Hostname resolution tests (including edge cases like trailing dots, invalid ports)

node/network_bridge.rs:

• ConnectionError variant tests (clone, display, debug, from conversions)
• Channel notification flow tests
• Channel capacity under load tests
• Sender cloning behavior tests

Files Still Needing Coverage

The following files have 0% coverage and would benefit from future test work:

• p2p_impl.rs - Requires network mocking
• p2p_protoc.rs - Requires libp2p protocol mocking
• in_memory.rs - Test infrastructure code

These are harder to test in isolation because they involve real network I/O and complex async coordination. The existing integration tests exercise much of this code.

Testing

All 78 node module tests pass:

cargo test --lib 'node::' -- --test-threads=4 test result: ok. 78 passed; 0 failed; 0 ignored 

[AI-assisted - Claude]

[iduartgomez]

idk if I fiund much utility in this kind of test tbh

[sanity]

Any of them or just this one?