fix(adapter): close final foundation review

harness/tht/adapters/vector/legacy_direct.py

@@ -7,6 +7,7 @@ from tht.ports.vector import (
     VectorHealth,
     VectorWriteRecord,
     VectorWriteUnavailable,
+    require_positive_limit,
 )
 from tht.vectorstore.store import VectorHit, VectorStore as TableVectorStore
 
@@ -26,8 +27,20 @@ class LegacyDirectVectorStore:
             with self._engine.connect() as connection:
                 connection.exec_driver_sql("SELECT 1")
         except Exception as exc:
-            return VectorHealth(ok=False, detail=str(exc))
-        return VectorHealth(ok=True)
+            return VectorHealth(
+                ok=False,
+                detail=str(exc),
+                read_configured=True,
+                read_reachable=False,
+                read_detail=str(exc),
+                expected_dimension=self._dim,
+            )
+        return VectorHealth(
+            ok=True,
+            read_configured=True,
+            read_reachable=True,
+            expected_dimension=self._dim,
+        )
 
     def search(
         self,
@@ -37,6 +50,7 @@ class LegacyDirectVectorStore:
         limit: int,
         kinds: list[str] | None = None,
     ) -> list[VectorHit]:
+        require_positive_limit(limit)
         hits: list[VectorHit] = []
         for collection in collections:
             table = TableVectorStore(