Add integration test timeout and flaky test retry mechanism

[jose-compu]

Description

Network-based integration tests (e.g., test_network_real.rs, test_tendermint_network.rs) involve async I/O and timers. Without proper timeout enforcement, these tests can hang indefinitely in CI. Additionally, UDP-based tests can be inherently flaky.

Proposed Changes

• Add #[tokio::test(flavor = "multi_thread", worker_threads = 2)] with explicit timeouts
• Consider using tokio::time::timeout wrappers in network tests
• Add retry logic or #[flaky_test] attributes for known-flaky network tests
• Document which tests require network access

Impact

More reliable CI and clearer test expectations.