fix(zigbee): default IEEE/Vendor/Model/LQI props to hidden, preserve user visibility

- New zigbee props (approve + first-time re-import) ship with visible=false
  so the canvas card stays clean. User opts in from the right panel.
- On re-import of an already-approved node, merge instead of overwrite:
  keys already present keep their visible flag (and any user-edited value
  is replaced with the freshly imported one), brand-new keys are appended
  hidden. Non-zigbee custom properties are preserved untouched.

backend/tests/test_zigbee_router.py

@@ -407,6 +407,8 @@ async def test_persist_pending_import_sets_coordinator_properties(db_session) ->
     ).scalar_one()
     keys = {p["key"]: p["value"] for p in coord.properties}
     assert keys == {"IEEE": "0xCOORD", "Vendor": "TI", "Model": "CC2652"}
+    # New zigbee props default to hidden — user opts in from the right panel.
+    assert all(p["visible"] is False for p in coord.properties)
 
 
 @pytest.mark.asyncio
@@ -453,6 +455,53 @@ async def test_persist_pending_import_skips_pending_for_approved_node(
     ).scalar_one()
     keys = {p["key"]: p["value"] for p in refreshed.properties}
     assert keys == {"IEEE": "0xR1", "Vendor": "TI", "Model": "CC2530", "LQI": "250"}
+    # Brand-new props on an existing Node start hidden.
+    assert all(p["visible"] is False for p in refreshed.properties)
+
+
+@pytest.mark.asyncio
+async def test_persist_pending_import_preserves_user_visibility(db_session) -> None:
+    """If user has already made props visible, re-import must not flip them back."""
+    from sqlalchemy import select
+
+    from app.api.routes.zigbee import _persist_pending_import
+    from app.db.models import Node
+
+    approved = Node(
+        label="router_1",
+        type="zigbee_router",
+        status="online",
+        check_method="none",
+        ieee_address="0xR1",
+        services=[],
+        properties=[
+            {"key": "IEEE", "value": "0xR1", "icon": None, "visible": True},
+            {"key": "Vendor", "value": "TI", "icon": None, "visible": True},
+            {"key": "Custom", "value": "kept", "icon": None, "visible": True},
+        ],
+    )
+    db_session.add(approved)
+    await db_session.commit()
+
+    bumped = [dict(n) for n in _PENDING_NODES]
+    bumped[1]["lqi"] = 99
+    bumped[1]["model"] = "CC2530"
+    await _persist_pending_import(db_session, bumped, _PENDING_EDGES)
+
+    refreshed = (
+        await db_session.execute(select(Node).where(Node.ieee_address == "0xR1"))
+    ).scalar_one()
+    by_key = {p["key"]: p for p in refreshed.properties}
+    # Existing keys keep their visibility (True).
+    assert by_key["IEEE"]["visible"] is True
+    assert by_key["Vendor"]["visible"] is True
+    # New key arrives hidden.
+    assert by_key["Model"]["visible"] is False
+    assert by_key["LQI"]["visible"] is False
+    assert by_key["LQI"]["value"] == "99"
+    # Non-zigbee user-added prop is preserved untouched.
+    assert by_key["Custom"]["value"] == "kept"
+    assert by_key["Custom"]["visible"] is True
 
 
 @pytest.mark.asyncio
@@ -477,6 +526,10 @@ async def test_persist_pending_import_refreshes_existing_coordinator_properties(
     keys = {p["key"]: p["value"] for p in coord.properties}
     assert keys["Vendor"] == "TI"
     assert keys["Model"] == "CC2652"
+    # Newly added keys on re-import default to hidden.
+    by_key = {p["key"]: p for p in coord.properties}
+    assert by_key["Vendor"]["visible"] is False
+    assert by_key["Model"]["visible"] is False
 
 
 @pytest.mark.asyncio