fix: ruff linting errors and add comprehensive test coverage for asset queries

- Fix unused imports in routes.py, asset.py, manager.py, asset_management.py, ingest.py
- Fix whitespace issues in upload.py, asset_info.py, ingest.py
- Fix typo in manager.py (stray character after result["asset"])
- Fix broken import in test_metadata.py (project_kv moved to asset_info.py)
- Add fixture override in queries/conftest.py for unit test isolation

Add 48 new tests covering all previously untested query functions:
- asset.py: upsert_asset, bulk_insert_assets
- cache_state.py: upsert_cache_state, delete_cache_states_outside_prefixes,
  get_orphaned_seed_asset_ids, delete_assets_by_ids, get_cache_states_for_prefixes,
  bulk_set_needs_verify, delete_cache_states_by_ids, delete_orphaned_seed_asset,
  bulk_insert_cache_states_ignore_conflicts, get_cache_states_by_paths_and_asset_ids
- asset_info.py: insert_asset_info, get_or_create_asset_info,
  update_asset_info_timestamps, replace_asset_info_metadata_projection,
  bulk_insert_asset_infos_ignore_conflicts, get_asset_info_ids_by_ids
- tags.py: bulk_insert_tags_and_meta

Total: 119 tests pass (up from 71)

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

app/assets/manager.py

@@ -28,9 +28,7 @@ from app.assets.api.upload import _cleanup_temp
 from app.assets.database.queries import (
     asset_exists_by_hash,
     fetch_asset_info_and_asset,
-    fetch_asset_info_asset_and_tags,
     get_asset_by_hash,
-    get_asset_info_by_id,
     get_asset_tags,
     list_asset_infos_page,
     list_cache_states_by_asset_id,
@@ -417,7 +415,7 @@ def set_asset_preview(
         owner_id=owner_id,
     )
     info = result["info"]
-    asset = result["asset"]T
+    asset = result["asset"]
     tags = result["tags"]
 
     return schemas_out.AssetDetail(