Add testing support and new utility function for target distribution

- Introduce a new function `modality_targets_from_target_dist` in `target_dist.py` to extract modality targets from a target distribution dictionary.
- Create a new test file `test_target_dist.py` with unit tests for the new function.
- Update `Makefile` to include a test command for running pytest.
- Modify `pyproject.toml` to configure pytest options.

Makefile

@@ -1,2 +1,5 @@
 run:
 	DEV_MODE=1 uv run gradio main.py
+
+test:
+	uv run pytest

inference_utils/target_dist.py

@@ -0,0 +1,2 @@
+def modality_targets_from_target_dist(target_dist: dict) -> dict:
+    return {modality: list(targets.keys()) for modality, targets in target_dist.items()}

pyproject.toml

@@ -8,3 +8,6 @@ dependencies = [
     "gradio==4.44.1",
     "pytest>=8.3.4",
 ]
+
+[tool.pytest.ini_options]
+pythonpath = ["."]

test_inference_utils/test_target_dist.py

@@ -0,0 +1,17 @@
+from inference_utils.target_dist import modality_targets_from_target_dist
+
+
+def test_target_dist_dict_to_modality_targets():
+    target_dist_dict = {
+        "CT-Abdomen": {"postcava": [[1, 2], [3, 4]], "aorta": [[5, 6], [7, 8]]},
+        "CT-Chest": {"nodule": [[9, 10], [11, 12]], "tumor": [[13, 14], [15, 16]]},
+    }
+
+    expected = {
+        "CT-Abdomen": ["postcava", "aorta"],
+        "CT-Chest": ["nodule", "tumor"],
+    }
+
+    actual = modality_targets_from_target_dist(target_dist_dict)
+
+    assert actual == expected