Add adaptive cost-quality routing primitives

tests/test_adaptive_integration.py

@@ -0,0 +1,90 @@
+"""
+Integration coverage for the adaptive routing workplan flow.
+"""
+
+from datetime import datetime, timezone
+
+from llm_connect.adapter import MockLLMAdapter
+from llm_connect.quality import QualityLedger, QualityObservation
+from llm_connect.routing import AdaptiveRoutingPolicy, RoutingRule
+
+
+def append_quality(
+    ledger: QualityLedger,
+    adapter_id: str,
+    quality_score: float,
+    cost_usd: float,
+    *,
+    recorded_at: datetime,
+) -> None:
+    ledger.append(
+        QualityObservation(
+            task_type="summarize",
+            adapter_id=adapter_id,
+            model_id=f"{adapter_id}-model",
+            cost_usd=cost_usd,
+            quality_score=quality_score,
+            latency_ms=100,
+            tokens_in=100,
+            tokens_out=50,
+            recorded_at=recorded_at,
+            baseline_adapter_id="baseline",
+        )
+    )
+
+
+def test_adaptive_policy_converges_to_cheapest_qualifying_adapter(tmp_path):
+    cheap = MockLLMAdapter("cheap")
+    mid = MockLLMAdapter("mid")
+    smart = MockLLMAdapter("smart")
+    ledger = QualityLedger(tmp_path / "quality.jsonl")
+    policy = AdaptiveRoutingPolicy(
+        rules=[
+            RoutingRule(
+                "summarize",
+                prefer=smart,
+                max_cost_per_1k=1.0,
+                fallback=mid,
+            )
+        ],
+        ledger=ledger,
+        adapters_by_id={"cheap": cheap, "mid": mid, "smart": smart},
+        window_size=2,
+    )
+
+    assert policy.resolve("summarize", quality_floor=0.8) is smart
+    assert policy.resolve("summarize", 2.0, quality_floor=0.8) is mid
+
+    append_quality(
+        ledger,
+        "cheap",
+        quality_score=0.7,
+        cost_usd=0.01,
+        recorded_at=datetime(2026, 5, 17, 10, tzinfo=timezone.utc),
+    )
+    append_quality(
+        ledger,
+        "mid",
+        quality_score=0.86,
+        cost_usd=0.02,
+        recorded_at=datetime(2026, 5, 17, 10, tzinfo=timezone.utc),
+    )
+    append_quality(
+        ledger,
+        "smart",
+        quality_score=0.95,
+        cost_usd=0.05,
+        recorded_at=datetime(2026, 5, 17, 10, tzinfo=timezone.utc),
+    )
+
+    assert policy.resolve("summarize", quality_floor=0.8) is mid
+
+    append_quality(
+        ledger,
+        "cheap",
+        quality_score=0.95,
+        cost_usd=0.01,
+        recorded_at=datetime(2026, 5, 17, 11, tzinfo=timezone.utc),
+    )
+
+    assert policy.resolve("summarize", quality_floor=0.8) is cheap