Runloop destination registry failover (2218750)

Prebuilt rules_img 0.3.20 tool binaries for Runloop's destination-registry failover fork.

Runloop destination registry failover (cd2fb50)

Temporary Runloop prerelease containing locally cross-built img binaries for destination_registry failover testing. Source: cd2fb50.

rules_img v0.3.19

Runloop-maintained v0.3.19 assets with idempotent immutable-tag reconciliation. A rejected tag push is accepted only when an authenticated registry HEAD resolves to the intended digest.