Function parse_json_field_or_warn 

pub(crate) fn parse_json_field_or_warn<T: DeserializeOwned + Default>(
    raw: &str,
    field_name: &str,
    warnings: &mut Vec<String>,
) -> T

Parse a db_bundles JSON column (context_files, instructions_by_provider), treating a blank/whitespace-only value as “genuinely no data” (not an error) but pushing a warning to warnings for anything non-blank that fails to parse, rather than silently discarding it via unwrap_or_default() — an export that quietly loses data defeats its own backup/portability purpose (#2333).