Initial standalone memabra release

tests/test_case_index.py

@@ -0,0 +1,50 @@
+from memabra.case_index import CaseIndex
+
+
+def test_case_index_adds_and_retrieves_best_trajectory():
+    index = CaseIndex()
+    trajectory = {
+        "trajectory_id": "traj-1",
+        "task": {"input": "Hello world"},
+        "outcome": {"status": "success"},
+        "reward": {"total": 1.0},
+    }
+    index.add(trajectory)
+    assert index.best("Hello world") == "traj-1"
+
+
+def test_case_index_returns_none_for_unknown_input():
+    index = CaseIndex()
+    assert index.best("Unknown input") is None
+
+
+def test_case_index_keeps_higher_reward_for_same_input():
+    index = CaseIndex()
+    index.add({
+        "trajectory_id": "traj-low",
+        "task": {"input": "Same input"},
+        "outcome": {"status": "success"},
+        "reward": {"total": 0.5},
+    })
+    index.add({
+        "trajectory_id": "traj-high",
+        "task": {"input": "Same input"},
+        "outcome": {"status": "success"},
+        "reward": {"total": 1.5},
+    })
+    assert index.best("Same input") == "traj-high"
+
+
+def test_case_index_save_and_round_trip(tmp_path):
+    index = CaseIndex()
+    index.add({
+        "trajectory_id": "traj-save",
+        "task": {"input": "Persist me"},
+        "outcome": {"status": "success"},
+        "reward": {"total": 2.0},
+    })
+    path = tmp_path / "case_index.json"
+    index.save(path)
+
+    loaded = CaseIndex.load(path)
+    assert loaded.best("Persist me") == "traj-save"