Phase 5: Migrate bootstrap and discovery tests

Create organized test structure for proactive sync:

tests/common/sync_helpers.rs (from Phase 4):
- TestClient with retry logic for connect/send
- Event builders: build_layer2_issue_event, build_layer3_comment_event
- Tag variants (a/A/q for Layer 2, e/E/q for Layer 3)
- wait_for_event_on_relay() assertion helper
- repo_coord() utility function
- Unit tests for all builders

tests/sync/mod.rs:
- Module organization for sync tests
- Documentation of test categories

tests/sync.rs:
- Main test harness including common and sync modules

tests/sync/bootstrap.rs:
- test_bootstrap_syncs_existing_layer2_events (Test 1)
- test_relay_replays_events_after_restart (Test 4)

tests/sync/discovery.rs:
- test_discovers_layer3_via_layer2 (Test 2)
- test_layer2_discovery_with_chain (Test 3 - simplified)

All 14 tests pass: cargo test --test sync

1 files changed, 29 insertions, 0 deletions

diff --git a/tests/sync.rs b/tests/sync.rs
new file mode 100644
index 0000000..cedb876
--- /dev/null
+++ b/tests/sync.rs
@@ -0,0 +1,29 @@
+//! Proactive Sync Integration Tests
+//!
+//! This test file organizes tests for ngit-grasp's proactive sync functionality.
+//! Tests are grouped into submodules by sync scenario:
+//!
+//! - `bootstrap` - Tests for sync from pre-configured bootstrap relay
+//! - `discovery` - Tests for relay discovery from announcement events
+//!
+//! # Running Tests
+//!
+//! ```bash
+//! # Run all sync tests
+//! cargo test --test sync
+//!
+//! # Run with output
+//! cargo test --test sync -- --nocapture
+//!
+//! # Run specific test
+//! cargo test --test sync test_bootstrap_syncs -- --nocapture
+//! ```
+
+// Include the common test utilities
+mod common;
+
+// Include sync test submodules (located in tests/sync/)
+mod sync {
+    pub mod bootstrap;
+    pub mod discovery;
+}
\ No newline at end of file