Function update_graph_with_tx 

pub fn update_graph_with_tx(
    tx: &Transaction<'_>,
    result: &AttributedRunResult,
    eval_id: &str,
    version_id: &str,
    config: &ForgeConfig,
) -> ForgeResult<UpdateResult>

Update the causal graph using an already-open transaction handle.

This avoids nested write transactions and keeps CEA writes inside the owning store transaction boundary.