fix(deps): make SeekDB optional for native installs

tests/unit_tests/vector/test_seekdb_optional.py

@@ -0,0 +1,34 @@
+from __future__ import annotations
+
+import importlib
+from unittest.mock import MagicMock
+
+import pytest
+
+from tests.utils.import_isolation import isolated_sys_modules
+
+
+_INSTALL_HINT = "Install LangBot with the 'seekdb' extra"
+
+
+def test_seekdb_vector_backend_reports_missing_optional_extra() -> None:
+    module_name = 'langbot.pkg.vector.vdbs.seekdb'
+
+    with isolated_sys_modules({'pyseekdb': None}, clear=[module_name]):
+        seekdb_module = importlib.import_module(module_name)
+
+        assert seekdb_module.SEEKDB_AVAILABLE is False
+        with pytest.raises(ImportError, match=_INSTALL_HINT):
+            seekdb_module.SeekDBVectorDatabase(MagicMock())
+
+
+@pytest.mark.asyncio
+async def test_seekdb_embedding_reports_missing_optional_extra() -> None:
+    module_name = 'langbot.pkg.provider.modelmgr.requesters.seekdbembed'
+
+    with isolated_sys_modules({'pyseekdb': None}, clear=[module_name]):
+        seekdb_embedding_module = importlib.import_module(module_name)
+        requester = seekdb_embedding_module.SeekDBEmbedding.__new__(seekdb_embedding_module.SeekDBEmbedding)
+
+        with pytest.raises(ImportError, match=_INSTALL_HINT):
+            await requester.initialize()