feat: expose multi-host runtime readiness

tests/test_operational_checks.py

@@ -52,11 +52,13 @@ def test_module_operational_check_failure_is_isolated() -> None:
         raise RuntimeError("secret detail")
 
     result = routes._module_operational_checks(
-        _Registry(OperationalCheckProviderRegistration(
-            module_id="example",
-            check_id="example.failed",
-            provider=provider,
-        )),
+        _Registry(
+            OperationalCheckProviderRegistration(
+                module_id="example",
+                check_id="example.failed",
+                provider=provider,
+            )
+        ),
         force=True,
     )[0]
 
@@ -82,3 +84,43 @@ def test_shared_runtime_cluster_missing_replicas_blocks_readiness() -> None:
     assert check["state"] == "error"
     assert check["readiness_critical"] is True
     assert check["metrics"]["recovery_required"] == 1
+
+
+def test_shared_runtime_cluster_skew_or_unserved_queue_blocks_readiness() -> None:
+    check = routes._runtime_cluster_check(
+        {
+            "available": True,
+            "state_profile": "shared",
+            "nodes": [],
+            "expected": {"api": 2, "worker": 2},
+            "active": {"api": 2, "worker": 2},
+            "composition": {"skewed": True},
+            "software_versions": {"skewed": False},
+            "queues": {"missing": ["calendar"]},
+            "recovery": {"requires_attention": 0},
+        }
+    )
+
+    assert check["state"] == "error"
+    assert check["readiness_critical"] is True
+    assert check["metrics"]["composition_skewed"] is True
+    assert check["metrics"]["missing_queues"] == 1
+
+
+def test_database_capacity_check_enforces_shared_rendered_budget(
+    monkeypatch,
+) -> None:
+    monkeypatch.setattr(routes.core_settings, "state_profile", "shared")
+    monkeypatch.setattr(routes.core_settings, "database_connection_limit", 100)
+    monkeypatch.setattr(routes.core_settings, "database_connection_reserve", 10)
+    monkeypatch.setattr(routes.core_settings, "database_connection_available", 90)
+    monkeypatch.setattr(routes.core_settings, "database_connection_peak", 70)
+
+    healthy = routes._database_capacity_check()
+    assert healthy["state"] == "ok"
+    assert healthy["metrics"]["peak"] == 70
+
+    monkeypatch.setattr(routes.core_settings, "database_connection_peak", 91)
+    overrun = routes._database_capacity_check()
+    assert overrun["state"] == "error"
+    assert overrun["readiness_critical"] is True