feat: add PageIndex SDK with local/cloud dual-mode support (#207)

tests/test_config.py

@@ -0,0 +1,28 @@
+# tests/test_config.py
+import pytest
+from pageindex.config import IndexConfig
+
+
+def test_defaults():
+    config = IndexConfig()
+    assert config.model == "gpt-4o-2024-11-20"
+    assert config.retrieve_model is None
+    assert config.toc_check_page_num == 20
+
+
+def test_overrides():
+    config = IndexConfig(model="gpt-5.4", retrieve_model="claude-sonnet")
+    assert config.model == "gpt-5.4"
+    assert config.retrieve_model == "claude-sonnet"
+
+
+def test_unknown_key_raises():
+    with pytest.raises(Exception):
+        IndexConfig(nonexistent_key="value")
+
+
+def test_model_copy_with_update():
+    config = IndexConfig(toc_check_page_num=30)
+    updated = config.model_copy(update={"model": "gpt-5.4"})
+    assert updated.model == "gpt-5.4"
+    assert updated.toc_check_page_num == 30