Integrate descriptor runtime candidates into harness

tests/test_mechanism_planner.py

@@ -4,7 +4,10 @@ import unittest
 
 from aituner.engine_adapters.vllm import default_vllm_descriptors
 from aituner.knob_descriptor import KnobConstraints, KnobDescriptor
-from aituner.mechanism_planner import coordinate_line_search_candidates
+from aituner.mechanism_planner import (
+    CoordinateSearchPolicy,
+    coordinate_line_search_candidates,
+)
 
 
 class MechanismPlannerTests(unittest.TestCase):
@@ -56,12 +59,26 @@ class MechanismPlannerTests(unittest.TestCase):
         descriptor = default_vllm_descriptors(tunable_flags=("gpu-memory-utilization",))[0]
 
         candidates = coordinate_line_search_candidates(
-            current_config={"gpu-memory-utilization": 0.98},
+            current_config={"gpu-memory-utilization": 0.96},
             descriptors=(descriptor,),
             evidence_weights={"kv_memory_capacity": 0.8},
         )
 
-        self.assertEqual(candidates[0].patch, {"gpu-memory-utilization": 1.0})
+        self.assertEqual(candidates[0].patch, {"gpu-memory-utilization": 0.97})
+
+    def test_coordinate_search_can_emit_larger_same_operator_steps(self) -> None:
+        descriptor = default_vllm_descriptors(tunable_flags=("max-num-seqs",))[0]
+
+        candidates = coordinate_line_search_candidates(
+            current_config={"max-num-seqs": 8},
+            descriptors=(descriptor,),
+            evidence_weights={"admission_capacity": 0.9},
+            policy=CoordinateSearchPolicy(step_multipliers=(1.0, 2.0)),
+        )
+
+        patches = [candidate.patch for candidate in candidates]
+        self.assertIn({"max-num-seqs": 16}, patches)
+        self.assertIn({"max-num-seqs": 24}, patches)
 
 
 if __name__ == "__main__":