Function capture_while_running 

pub(crate) fn capture_while_running(
    fs: &FileStore,
    uid: &str,
    dir: &Path,
    settle: Duration,
) -> Result<usize, StoreError>

Record what the provider wrote to dir while the agent runs — the drift detector’s hook (SPEC_MEMORY_FOLLOWS_THE_AGENT_2026_09_24.md §2.1.3). Capture only: nothing is written to the folder. Only a folder a spawn has already reconciled (it holds projections), whose claim uid still holds alone, and only files unchanged for settle (CAPTURE_SETTLE). Returns how many versions were recorded.