Tracoor only handles OnBlock and OnChainReOrg events but was subscribing
to all default beacon topics including attestation, single_attestation,
head, finalized_checkpoint, voluntary_exit, contribution_and_proof,
blob_sidecar, and block_gossip — all of which were received and silently
discarded.

The curl commands that scrape Kurtosis source for Docker image versions
can silently fail in CI (rate limiting, transient network issues),
leaving version variables empty and causing invalid Docker references.
Add --retry 3 to all curl commands and fail fast with a clear error
if any version is empty.