Function apply_post_commit_effects 

pub async fn apply_post_commit_effects(
    runtime: &KhiveRuntime,
    token: &NamespaceToken,
    effects: Vec<PostCommitEffect>,
) -> RuntimeResult<()>

Run every deferred PostCommitEffect after a committed atomic unit, outside any transaction. Re-fetches each target’s now-committed row and reuses the existing reindex_entity/reindex_note (FTS + embedding, same as the non-atomic path) for exact parity.