## Why
`CreateProcessWithLogonW` failures with `ERROR_SERVICE_ALREADY_RUNNING` (1056) previously aborted sandbox startup without retrying. At this stage, neither the runner nor the user command has started, so retrying does not replay the command.
## What changed
Retry runner creation once with the same sandbox credentials when logon returns error 1056. Propagate a second failure without refreshing credentials, and keep child startup errors with the same code ineligible for this retry.
## Testing
Add regression tests for recovery, the two-attempt limit, and exclusion of child startup failures. Add a unified exec test that injects a logon failure, verifies that the retry preserves the original request and credentials, and checks that the command runs exactly once.
GitOrigin-RevId: 78def6cdb93bf32f9b4a3e398cd16de83286fec4
zm-oai
26dd19ef47