Function manifest_generation_from_source_detail 

fn manifest_generation_from_source_detail(source_detail: &str) -> u64

Extracts a {"manifest_version": N} field from a version row’s source_detail JSON, defaulting to 0 when absent or unparseable — so a pre-existing row seeded before this field existed is always treated as generation 0, never blocking a real (>=1) manifest generation from writing over it. Shared convention between bundle_reseed_system_if_ owned’s own generation guard and any seeder populating source_detail (see operator_config_seed.rs).