feat: add spindle direction selection contract

tests/test_spindle_direction_contract.py

@@ -0,0 +1,33 @@
+import json
+from pathlib import Path
+
+from polisher_control.contracts import SpindleDirection, normalize_spindle_direction
+from polisher_control.telemetry_channels import RECOMMENDED_CHANNELS
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+def test_spindle_direction_enum_uses_stable_wire_values():
+    assert SpindleDirection.CLOCKWISE.value == "cw"
+    assert SpindleDirection.COUNTER_CLOCKWISE.value == "ccw"
+    assert SpindleDirection.allowed_values() == ["cw", "ccw"]
+
+
+def test_normalize_spindle_direction_accepts_operator_aliases():
+    assert normalize_spindle_direction("cw") == SpindleDirection.CLOCKWISE
+    assert normalize_spindle_direction("clockwise") == SpindleDirection.CLOCKWISE
+    assert normalize_spindle_direction("ccw") == SpindleDirection.COUNTER_CLOCKWISE
+    assert normalize_spindle_direction("counter-clockwise") == SpindleDirection.COUNTER_CLOCKWISE
+
+
+def test_spindle_direction_is_in_controller_job_segment_schema():
+    schema = json.loads((ROOT / "shared/schemas/controller-job.schema.json").read_text())
+    segment = schema["$defs"]["segment"]
+
+    assert "commanded_spindle_direction" in segment["required"]
+    assert segment["properties"]["commanded_spindle_direction"]["enum"] == ["cw", "ccw"]
+
+
+def test_spindle_direction_is_logged_as_telemetry_context():
+    assert "spindle_direction_setpoint" in RECOMMENDED_CHANNELS
+    assert "spindle_direction_actual" in RECOMMENDED_CHANNELS