Pete

### Is your proposal related to a problem? When `compact.go` fails to download a block the following error is displayed: ```json {"caller":"compact.go:570","err":"compaction: group 0@10000000000000000: download block 123456789ABCDEFG: context canceled","level":"error","msg":"retriable error","ts":"2025-06-06T03:06:06.14541332Z"}...

**Motivation** Allow for consistent JSON log output simplifying message parsing as well as formatting in markdown and other tools that can pretty format log lines. **Feature** Add a command line...