fix perspective correction

tests/node_tests/perspective_correction.py

@@ -51,3 +51,57 @@ def test_output_shape():
         bottom_right_x=0.0, bottom_right_y=0.0,
     )
     assert result.data.shape == (48, 96)
+
+
+def test_emits_perspective_overlay():
+    from backend.execution_context import active_node, execution_callbacks
+    from backend.nodes.perspective_correction import PerspectiveCorrection
+
+    node = PerspectiveCorrection()
+    field = make_field(shape=(64, 64))
+
+    overlays = []
+    with execution_callbacks(overlay=lambda nid, d: overlays.append(d)), active_node("test"):
+        node.process(
+            field,
+            top_left_x=0.05, top_left_y=0.05,
+            top_right_x=-0.05, top_right_y=0.05,
+            bottom_left_x=0.05, bottom_left_y=-0.05,
+            bottom_right_x=-0.05, bottom_right_y=-0.05,
+        )
+
+    assert len(overlays) == 1
+    ov = overlays[0]
+    assert ov["kind"] == "perspective"
+    assert ov["section_title"] == "Perspective"
+    assert ov["image"].startswith("data:image/png;base64,")
+    assert ov["corrected_image"].startswith("data:image/png;base64,")
+    assert len(ov["corners"]) == 4
+    assert ov["corners"][0] == {"x": 0.05, "y": 0.05}
+    assert ov["corners"][3] == {"x": -0.05, "y": -0.05}
+
+
+def test_coord_input_overrides_floats():
+    from backend.nodes.perspective_correction import PerspectiveCorrection
+
+    node = PerspectiveCorrection()
+    field = make_field(shape=(64, 64))
+
+    result_floats, = node.process(
+        field,
+        top_left_x=0.1, top_left_y=0.1,
+        top_right_x=0.0, top_right_y=0.0,
+        bottom_left_x=0.0, bottom_left_y=0.0,
+        bottom_right_x=0.0, bottom_right_y=0.0,
+    )
+
+    result_coord, = node.process(
+        field,
+        top_left_x=0.0, top_left_y=0.0,
+        top_right_x=0.0, top_right_y=0.0,
+        bottom_left_x=0.0, bottom_left_y=0.0,
+        bottom_right_x=0.0, bottom_right_y=0.0,
+        top_left=(0.1, 0.1),
+    )
+
+    assert np.allclose(result_floats.data, result_coord.data)