refactor: use query functions instead of direct ORM modifications in service layer

Add update_asset_info_name and update_asset_info_updated_at query functions
and update asset_management.py to use them instead of modifying ORM objects
directly. This ensures the service layer only uses explicit operations from
the queries package.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/assets/database/queries/__init__.py

@@ -18,6 +18,8 @@ from app.assets.database.queries.asset_info import (
     fetch_asset_info_asset_and_tags,
     fetch_asset_info_and_asset,
     update_asset_info_access_time,
+    update_asset_info_name,
+    update_asset_info_updated_at,
     set_asset_info_metadata,
     delete_asset_info_by_id,
     set_asset_info_preview,
@@ -68,6 +70,8 @@ __all__ = [
     "fetch_asset_info_asset_and_tags",
     "fetch_asset_info_and_asset",
     "update_asset_info_access_time",
+    "update_asset_info_name",
+    "update_asset_info_updated_at",
     "set_asset_info_metadata",
     "delete_asset_info_by_id",
     "set_asset_info_preview",

app/assets/database/queries/asset_info.py

@@ -400,6 +400,34 @@ def update_asset_info_access_time(
     session.execute(stmt.values(last_access_time=ts))
 
 
+def update_asset_info_name(
+    session: Session,
+    asset_info_id: str,
+    name: str,
+) -> None:
+    """Update the name of an AssetInfo."""
+    now = get_utc_now()
+    session.execute(
+        sa.update(AssetInfo)
+        .where(AssetInfo.id == asset_info_id)
+        .values(name=name, updated_at=now)
+    )
+
+
+def update_asset_info_updated_at(
+    session: Session,
+    asset_info_id: str,
+    ts: datetime | None = None,
+) -> None:
+    """Update the updated_at timestamp of an AssetInfo."""
+    ts = ts or get_utc_now()
+    session.execute(
+        sa.update(AssetInfo)
+        .where(AssetInfo.id == asset_info_id)
+        .values(updated_at=ts)
+    )
+
+
 def set_asset_info_metadata(
     session: Session,
     asset_info_id: str,

app/assets/services/asset_management.py

@@ -29,6 +29,8 @@ from app.assets.database.queries import (
     set_asset_info_metadata,
     set_asset_info_preview,
     set_asset_info_tags,
+    update_asset_info_name,
+    update_asset_info_updated_at,
 )
 
 
@@ -78,7 +80,7 @@ def update_asset_metadata(
 
         touched = False
         if name is not None and name != info.name:
-            info.name = name
+            update_asset_info_name(session, asset_info_id=asset_info_id, name=name)
             touched = True
 
         # Compute filename from best live path
@@ -111,8 +113,7 @@ def update_asset_metadata(
             touched = True
 
         if touched and user_metadata is None:
-            info.updated_at = get_utc_now()
+            update_asset_info_updated_at(session, asset_info_id=asset_info_id)
-            session.flush()
 
         # Fetch updated info with tags
         result = fetch_asset_info_asset_and_tags(