Fix visualizer coercion for multibyte hops

tests/test_contacts_router.py

@@ -326,6 +326,28 @@ class TestContactDetail:
         assert repeater["name"] == "Relay1"
         assert repeater["heard_count"] == 2
 
+    @pytest.mark.asyncio
+    async def test_detail_nearest_repeaters_use_full_multibyte_next_hop(self, test_db, client):
+        """Nearest repeater resolution should distinguish multi-byte hops with the same first byte."""
+        await _insert_contact(KEY_A, "Alice", type=1)
+        repeater_1 = "bb11" + "aa" * 30
+        repeater_2 = "bb22" + "cc" * 30
+        await _insert_contact(repeater_1, "Relay11", type=2)
+        await _insert_contact(repeater_2, "Relay22", type=2)
+
+        await ContactAdvertPathRepository.record_observation(KEY_A, "bb221122", 1000, hop_count=2)
+        await ContactAdvertPathRepository.record_observation(KEY_A, "bb223344", 1010, hop_count=2)
+
+        response = await client.get(f"/api/contacts/{KEY_A}/detail")
+
+        assert response.status_code == 200
+        data = response.json()
+        assert len(data["nearest_repeaters"]) == 1
+        repeater = data["nearest_repeaters"][0]
+        assert repeater["public_key"] == repeater_2
+        assert repeater["name"] == "Relay22"
+        assert repeater["heard_count"] == 2
+
     @pytest.mark.asyncio
     async def test_detail_advert_frequency_computed(self, test_db, client):
         """Advert frequency is computed from path observations over time span."""

tests/test_repository.py

@@ -273,6 +273,19 @@ class TestContactAdvertPathRepository:
         assert paths[0].last_seen == 1010
         assert paths[0].heard_count == 2
 
+    @pytest.mark.asyncio
+    async def test_record_observation_preserves_full_multibyte_next_hop(self, test_db):
+        repeater_key = "ab" * 32
+        await ContactRepository.upsert({"public_key": repeater_key, "name": "Rmulti", "type": 2})
+
+        await ContactAdvertPathRepository.record_observation(
+            repeater_key, "aa11bb22", 1000, hop_count=2
+        )
+
+        paths = await ContactAdvertPathRepository.get_recent_for_contact(repeater_key, limit=10)
+        assert len(paths) == 1
+        assert paths[0].next_hop == "aa11"
+
     @pytest.mark.asyncio
     async def test_prunes_to_most_recent_n_unique_paths(self, test_db):
         repeater_key = "bb" * 32