只有hello包实现多跳，还没加入业务数据

具体的还要看opencode和gpt记录接着优化

sim/tests/test_multihop_exists.py

@@ -0,0 +1,49 @@
+"""
+Test: Multihop Exists
+
+Assert:
+- max_hop >= 2
+
+This verifies that multi-hop routing is actually being used.
+"""
+
+import pytest
+import random
+
+from sim.main import run_simulation
+from sim import config
+
+
+@pytest.fixture
+def seed():
+    return 42
+
+
+def test_multihop_exists(seed):
+    """Test that multi-hop routing is formed (hop >= 2)."""
+    results = run_simulation(num_nodes=12, area_size=800, sim_time=200, seed=seed)
+
+    metrics = results["metrics"]
+    max_hop = metrics.get("max_hop", 0)
+
+    print(f"Max hop: {max_hop}")
+    print(f"Hop distribution: {metrics.get('hop_histogram', {})}")
+
+    assert max_hop >= 2, f"Multi-hop not formed: max_hop={max_hop}"
+
+
+def test_multihop_with_hop_histogram(seed):
+    """Test hop distribution shows multiple hops."""
+    results = run_simulation(num_nodes=12, area_size=800, sim_time=300, seed=seed)
+
+    metrics = results["metrics"]
+    hop_histogram = metrics.get("hop_histogram", {})
+
+    print(f"Hop histogram: {hop_histogram}")
+
+    # Should have at least 2 different hop counts
+    assert len(hop_histogram) >= 1, "No hop distribution data"
+
+
+if __name__ == "__main__":
+    pytest.main([__file__, "-v", "-s"])