fix(cache): close the connection the schema init opened

`with sqlite3.Connection` ends the transaction but keeps the file handle open,
so every cache class leaked one handle per instance until the garbage collector
happened to run. On Windows that makes the database file undeletable while the
process lives (WinError 32), which broke 30 cache tests in teardown and would
also block moving or clearing a cache at runtime.

All eight `with <connection>` sites now go through `closing_connection()`, and a
regression test asserts the schema init leaves no usable connection behind.

py/services/download_queue_service.py

@@ -8,6 +8,7 @@ import sqlite3
 import time
 from typing import Any, List, Optional
 
+from ..utils.cache_db import closing_connection
 from ..utils.cache_paths import get_cache_base_dir
 
 logger = logging.getLogger(__name__)
@@ -127,7 +128,7 @@ class DownloadQueueService:
     def _initialize_schema(self) -> None:
         if self._schema_initialized:
             return
-        with self._connect() as conn:
+        with closing_connection(self._connect()) as conn:
             conn.executescript(self._SCHEMA_TABLES)
 
             # Databases created by older versions lack

py/services/downloaded_version_history_service.py

@@ -11,6 +11,7 @@ import sqlite3
 import time
 from typing import Iterable, Mapping, Optional, Sequence
 
+from ..utils.cache_db import closing_connection
 from ..utils.cache_paths import get_cache_base_dir
 from .settings_manager import get_settings_manager
 
@@ -100,7 +101,7 @@ class DownloadedVersionHistoryService:
     def _initialize_schema(self) -> None:
         if self._schema_initialized:
             return
-        with self._connect() as conn:
+        with closing_connection(self._connect()) as conn:
             conn.executescript(self._SCHEMA)
             conn.commit()
         self._schema_initialized = True

py/services/model_update_service.py

@@ -17,6 +17,7 @@ from typing import Any, Dict, Iterable, Iterator, List, Mapping, Optional, Seque
 
 from .errors import RateLimitError, ResourceNotFoundError
 from .settings_manager import get_settings_manager
+from ..utils.cache_db import closing_connection
 from ..utils.cache_paths import CacheType, resolve_cache_path_with_migration
 from ..utils.constants import MODEL_WEIGHT_FILE_TYPES
 from ..utils.civitai_utils import rewrite_preview_url
@@ -445,7 +446,7 @@ class ModelUpdateService:
         if self._schema_initialized:
             return
         try:
-            with self._connect() as conn:
+            with closing_connection(self._connect()) as conn:
                 conn.execute("PRAGMA journal_mode=WAL")
                 conn.execute("PRAGMA foreign_keys = ON")
                 conn.executescript(self._SCHEMA)
@@ -484,7 +485,7 @@ class ModelUpdateService:
             return
 
         try:
-            with sqlite3.connect(legacy_path, check_same_thread=False) as legacy_conn:
+            with closing_connection(sqlite3.connect(legacy_path, check_same_thread=False)) as legacy_conn:
                 legacy_conn.row_factory = sqlite3.Row
                 status_rows = legacy_conn.execute(
                     """
@@ -2315,7 +2316,7 @@ class ModelUpdateService:
         status_rows: list[sqlite3.Row] = []
         version_rows: list[sqlite3.Row] = []
 
-        with self._connect() as conn:
+        with closing_connection(self._connect()) as conn:
             for start in range(0, len(ids), self._SQLITE_MAX_VARIABLES):
                 chunk = tuple(ids[start : start + self._SQLITE_MAX_VARIABLES])
                 placeholders = ",".join("?" for _ in chunk)
@@ -2418,7 +2419,7 @@ class ModelUpdateService:
             record.last_checked_at,
             1 if record.should_ignore_model else 0,
         )
-        with self._connect() as conn:
+        with closing_connection(self._connect()) as conn:
             conn.execute(
                 """
                 INSERT INTO model_update_status (

py/services/persistent_model_cache.py

@@ -6,7 +6,7 @@ import threading
 from dataclasses import dataclass, field
 from typing import Any, Dict, List, Mapping, Optional, Sequence, Set, Tuple
 
-from ..utils.cache_db import connect_cache_db
+from ..utils.cache_db import closing_connection, connect_cache_db
 from ..utils.cache_paths import CacheType, resolve_cache_path_with_migration
 from ..utils.file_lock import exclusive_lock
 from ..utils.root_paths import normalize_root_identity
@@ -618,7 +618,7 @@ class PersistentModelCache:
             if self._schema_initialized:
                 return
             try:
-                with self._connect() as conn:
+                with closing_connection(self._connect()) as conn:
                     conn.execute("PRAGMA journal_mode=WAL")
                     conn.execute("PRAGMA foreign_keys = ON")
                     conn.executescript(

py/services/persistent_recipe_cache.py

@@ -19,7 +19,7 @@ import threading
 from dataclasses import dataclass, field
 from typing import Any, Dict, List, Optional, Set, Tuple
 
-from ..utils.cache_db import connect_cache_db
+from ..utils.cache_db import closing_connection, connect_cache_db
 from ..utils.cache_paths import CacheType, resolve_cache_path_with_migration
 from ..utils.file_lock import exclusive_lock
 
@@ -457,7 +457,7 @@ class PersistentRecipeCache:
             if self._schema_initialized:
                 return
             try:
-                with self._connect() as conn:
+                with closing_connection(self._connect()) as conn:
                     conn.execute("PRAGMA journal_mode=WAL")
                     conn.execute("PRAGMA foreign_keys = ON")
                     conn.executescript(

py/utils/cache_db.py

@@ -14,7 +14,8 @@ the write path in WAL so readers are never blocked by a writer.
 from __future__ import annotations
 
 import sqlite3
-from typing import Any
+from contextlib import contextmanager
+from typing import Any, Iterator
 
 # How long a connection waits for a competing writer before raising.
 CONCURRENT_TIMEOUT_SECONDS = 30.0
@@ -79,3 +80,19 @@ def connect_cache_db(
         pass
 
     return conn
+
+
+@contextmanager
+def closing_connection(conn: sqlite3.Connection) -> Iterator[sqlite3.Connection]:
+    """Yield *conn* and close it on exit.
+
+    ``with sqlite3.Connection`` only ends the transaction: it leaves the file
+    handle open, and a live handle keeps the cache database undeletable on
+    Windows (``WinError 32``) until the garbage collector happens to run. Every
+    ``with`` over a cache connection goes through here instead.
+    """
+
+    try:
+        yield conn
+    finally:
+        conn.close()