feat(discovery): preserve existing advert metadata during discovery result persistence

Enhanced the `persist_discovery_result` function to retain advert metadata such as `node_name`, `latitude`, and `longitude` from existing records when updating neighbor information. This prevents overwriting valuable metadata with `None` values during SQLite updates. Added a corresponding test to verify that existing metadata is preserved correctly during the discovery process.

repeater/handler_helpers/discovery.py

@@ -93,6 +93,26 @@ def persist_discovery_result(storage, result: dict) -> bool:
         logger.debug("Storage backend cannot persist discovery results")
         return False
 
+    # Discovery responses do not carry advert metadata such as name or location.
+    # Preserve those fields from an existing advert instead of replacing them
+    # with None when SQLite updates the neighbor row.
+    reader = getattr(storage, "get_neighbors", None)
+    if callable(reader):
+        try:
+            neighbors = reader()
+            if isinstance(neighbors, dict):
+                existing = neighbors.get(record["pubkey"])
+                if isinstance(existing, dict):
+                    for field in ("node_name", "latitude", "longitude"):
+                        if record.get(field) is None:
+                            record[field] = existing.get(field)
+        except Exception as e:
+            logger.debug(
+                "Failed to read existing discovery metadata for %s: %s",
+                record["pubkey"][:8],
+                e,
+            )
+
     try:
         writer(record)
         return True

tests/test_handler_helpers_mesh_cli.py

@@ -513,6 +513,47 @@ def test_discovery_auto_add_persists_through_the_storage_actually_wired_in():
     assert record["rssi"] == -70
 
 
+def test_discovery_auto_add_preserves_existing_advert_name_and_location(tmp_path):
+    """Discovery responses must not erase metadata learned from real adverts."""
+    from repeater.data_acquisition.sqlite_handler import SQLiteHandler
+    from repeater.handler_helpers.discovery import persist_discovery_result
+
+    pubkey = "22" * 32
+    storage = SQLiteHandler(tmp_path)
+    storage.store_advert(
+        {
+            "timestamp": 100.0,
+            "pubkey": pubkey,
+            "node_name": "Named Repeater",
+            "is_repeater": True,
+            "route_type": 1,
+            "contact_type": "Repeater",
+            "latitude": 37.5,
+            "longitude": -122.25,
+            "rssi": -80,
+            "snr": 2.0,
+            "zero_hop": True,
+        }
+    )
+
+    assert persist_discovery_result(
+        storage,
+        {
+            "pub_key": pubkey,
+            "node_type": 2,
+            "rssi": -65,
+            "response_snr": 6.5,
+        },
+    )
+
+    neighbor = storage.get_neighbors()[pubkey]
+    assert neighbor["node_name"] == "Named Repeater"
+    assert neighbor["latitude"] == 37.5
+    assert neighbor["longitude"] == -122.25
+    assert neighbor["rssi"] == -65
+    assert neighbor["snr"] == 6.5
+
+
 def test_discovery_auto_add_prefers_record_advert_when_the_collector_is_wired_in():
     """StorageCollector.record_advert also publishes the advert; prefer it."""
     from repeater.data_acquisition.storage_collector import StorageCollector