code quality improvements

[0x0Glitch]

This PR includes three improvements :

1. Fix error handling in tar writer during Docker builds - Previously, errors from Flush() and Close() operations on the tar writer in archiveFS were ignored, potentially leading to corrupted Docker builds. Now these errors are properly handled and propagated to the caller.

2. Add timestamps to client log filenames - Client logs now include UTC timestamps in their filenames, making it easier to track logs chronologically and preventing potential log file collisions when containers are restarted.(as written in TODO)

3. Remove unused MAC field from ContainerInfo struct - The MAC field was marked with a TODO for removal and wasn't used anywhere in the codebase except for assignments.

[0x0Glitch]

Hello @KolbyML,Please have a look at these changes if they make sense.

[KolbyML]

Hello @KolbyML,Please have a look at these changes if they make sense.

Hi @0x0Glitch I already responded to your message on Telegram. I don't maintain this code so I can't review your PR as I said before.

[0x0Glitch]

Hello @fjl ,Please have a look at these changes if they make sense.