refactor: improve function naming for clarity and consistency

Rename functions to use clearer verb-based names:
- pick_best_live_path → select_best_live_path
- escape_like_prefix → escape_sql_like_string
- list_tree → list_files_recursively
- check_asset_file_fast → verify_asset_file_unchanged
- _seed_from_paths_batch → _batch_insert_assets_from_paths
- reconcile_cache_states_for_root → sync_cache_states_with_filesystem
- touch_asset_info_by_id → update_asset_info_access_time
- replace_asset_info_metadata_projection → set_asset_info_metadata
- expand_metadata_to_rows → convert_metadata_to_rows
- _rows_per_stmt → _calculate_rows_per_statement
- ensure_within_base → validate_path_within_base
- _cleanup_temp → _delete_temp_file_if_exists
- validate_hash_format → normalize_and_validate_hash
- get_relative_to_root_category_path_of_asset → get_asset_category_and_relative_path

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

app/assets/helpers.py

@@ -3,7 +3,7 @@ from datetime import datetime, timezone
 from typing import Literal, Sequence
 
 
-def pick_best_live_path(states: Sequence) -> str:
+def select_best_live_path(states: Sequence) -> str:
     """
     Return the best on-disk path among cache states:
       1) Prefer a path that exists with needs_verify == False (already verified).
@@ -22,7 +22,7 @@ def pick_best_live_path(states: Sequence) -> str:
 ALLOWED_ROOTS: tuple[Literal["models", "input", "output"], ...] = ("models", "input", "output")
 
 
-def escape_like_prefix(s: str, escape: str = "!") -> tuple[str, str]:
+def escape_sql_like_string(s: str, escape: str = "!") -> tuple[str, str]:
     """Escapes %, _ and the escape char itself in a LIKE prefix.
     Returns (escaped_prefix, escape_char). Caller should append '%' and pass escape=escape_char to .like().
     """