Function join_all_with_timeout 

pub async fn join_all_with_timeout<T>(
    name: impl Into<String>,
    timeout: Duration,
    handles: Vec<JoinHandle<T>>,
) -> Vec<CheckResult>

Verify that all spawned tasks finish within the given timeout.

Pass a vector of JoinHandles. Returns one CheckResult per task, each tagged async with numeric Evidence for the index and timeout / elapsed.

Verdicts:

• Task completed -> Pass, with elapsed_ms evidence.
• Task panicked or was cancelled -> Fail (Critical), with task_panicked tag.
• Task did not finish in time -> Fail (Error), with timeout tag.