test(app): add coverage for unique table row key generation

tests/app/test_app_table_row_keys.py

@@ -0,0 +1,34 @@
+from __future__ import annotations
+
+from auditui.app.table import AppTableMixin
+
+
+class DummyTableApp(AppTableMixin):
+    """Minimal host exposing library client for row key helper tests."""
+
+    def __init__(self) -> None:
+        """Initialize a fake library client with ASIN extraction."""
+        self.library_client = type(
+            "Library",
+            (),
+            {"extract_asin": lambda self, item: item.get("asin")},
+        )()
+
+
+def test_build_row_key_prefers_asin_and_remains_unique() -> None:
+    """Ensure duplicate ASINs receive deterministic unique key suffixes."""
+    app = DummyTableApp()
+    used: set[str] = set()
+    item = {"asin": "ASIN1"}
+    first = app._build_row_key(item, "Title", 0, used)
+    second = app._build_row_key(item, "Title", 1, used)
+    assert first == "ASIN1"
+    assert second == "ASIN1#2"
+
+
+def test_build_row_key_falls_back_to_title_and_index() -> None:
+    """Ensure missing ASIN values use title-index fallback keys."""
+    app = DummyTableApp()
+    used: set[str] = set()
+    key = app._build_row_key({"asin": None}, "Unknown Title", 3, used)
+    assert key == "Unknown Title#3"