Flightctl: flightctl: package-global go-git https transport mutated per-repo -- cross-tenant tls-config bleed

A flaw was found in flightctl. The configureRepoHTTPSClient() function in the device-render worker builds a per-repository tls.Config (which may include InsecureSkipVerify, a custom CA bundle, or tenant-supplied mTLS client certificates) and installs it into go-git's process-global client.Protocols map via gitclient.InstallProtocol("https", ...). Because the worker renders devices for multiple organizations concurrently from a shared goroutine pool, whichever tenant's repository configuration is written last wins for all in-flight git.Clone calls. This race condition can cause one tenant's TLS settings, including InsecureSkipVerify or mTLS client credentials, to leak into another tenant's git operations.