fix: support qdrant-only vector maintenance

harness/tht/adapters/vector/pgvector.py

@@ -3,8 +3,10 @@
 import json
 import re
 
+from psycopg2 import Error as PsycopgError
 from psycopg2 import sql
 from sqlalchemy import Engine
+from sqlalchemy.exc import SQLAlchemyError
 
 from tht.config import DatabaseConfig
 from tht.db.connection import make_engine
@@ -19,7 +21,6 @@ from tht.ports.vector import (
 )
 from tht.vectorstore.store import VectorHit, hit_from_metadata
 
-
 COLLECTION_KINDS = {
     "schema_records": {"schema_table", "schema_column"},
     "evidence": {"evidence"},
@@ -243,7 +244,7 @@ class PgVectorStore:
                 return True, None, dimensions
             finally:
                 raw.close()
-        except Exception as exc:
+        except (AttributeError, TypeError, ValueError, PsycopgError, SQLAlchemyError) as exc:
             return False, f"vector database probe failed: {type(exc).__name__}", set()
 
     def health(self) -> VectorHealth:
@@ -471,6 +472,30 @@ class PgVectorStore:
             if raw is not None:
                 raw.close()
 
+    def delete_kinds(self, collection: str, kinds: list[str]) -> int:
+        _collection(self._schema, collection)
+        _validate_collection_kinds(collection, kinds)
+        raw = None
+        try:
+            raw = self._require_writer().raw_connection()
+            with raw.cursor() as cursor:
+                cursor.execute(
+                    sql.SQL("DELETE FROM {} WHERE kind = ANY(%s)").format(
+                        _collection(self._schema, collection)
+                    ),
+                    (kinds,),
+                )
+                count = cursor.rowcount
+            raw.commit()
+            return count
+        except Exception as exc:
+            if raw is not None:
+                raw.rollback()
+            raise VectorWriteUnavailable("Vector kind cleanup unavailable") from exc
+        finally:
+            if raw is not None:
+                raw.close()
+
     def list_evidence_generations(self, collection: str, workspace_id: str) -> list[str]:
         if collection != "evidence":
             raise VectorStoreError("Only exact Evidence generations may be listed")