fix(adapter): close final foundation review

harness/tht/ports/vector.py

@@ -18,6 +18,15 @@ class VectorCapabilities:
 class VectorHealth:
     ok: bool
     detail: str | None = None
+    read_configured: bool = False
+    read_reachable: bool | None = None
+    read_detail: str | None = None
+    write_configured: bool = False
+    write_reachable: bool | None = None
+    write_detail: str | None = None
+    expected_dimension: int | None = None
+    observed_dimensions: tuple[int, ...] = ()
+    dimension_compatible: bool | None = None
 
 
 @dataclass(frozen=True)
@@ -37,6 +46,16 @@ class VectorWriteUnavailable(VectorStoreError):
     """Raised when a deployment has no vector writer credential."""
 
 
+class VectorReadUnavailable(VectorStoreError):
+    """Raised when a deployment has no vector reader credential."""
+
+
+def require_positive_limit(limit: int) -> None:
+    """Reject coercible values: vector limits are exact positive integers."""
+    if type(limit) is not int or limit <= 0:
+        raise ValueError("Vector search limit must be a positive integer")
+
+
 @runtime_checkable
 class VectorStore(Protocol):
     @property
@@ -63,6 +82,7 @@ __all__ = [
     "VectorHealth",
     "VectorHit",
     "VectorRecord",
+    "VectorReadUnavailable",
     "VectorStore",
     "VectorStoreError",
     "VectorWriteRecord",