fix(cli): print farewell after successful cleanup

[dcavalcante]

What does this PR do?

This is a follow-up to #110 and addresses the cleanup ordering noted in this review comment.

PR #110 correctly removed the farewell from --help and --version, but moved it into RunE, before PersistentPostRunE closes the application, database client, and logger. If cleanup fails, the farewell is printed before the command returns an error.

This change moves the farewell to the end of PersistentPostRunE, so it is printed only after cleanup succeeds.

Because persistent hooks can also run for child commands, the farewell is limited to the root command. This keeps future non-interactive commands, such as pgxcli export, from including the interactive farewell in their output.

Reproduction

Using the default history path:

touch ~/.pgxcli_history.jsonl
chmod a-w ~/.pgxcli_history.jsonl
go run . <connection arguments>

Exit pgxcli with \q.

On the current main, the farewell is printed before the history-save error. With this change, only the error is printed.

Remember to restore the file permissions:

chmod u+w ~/.pgxcli_history.jsonl

[balajz]

Thank you, Daniel. One more thing I noticed is that when closing resources such as the DB, logger, etc, the current implementation exits the function as soon as an error occurs while closing a resource and prints the close error.

To make it more robust, how about collecting any errors that occur while closing the resources and returning them all at the end, if there are any? In that case, the output would be something like:

go run .
Thanks for using Pgxcli.
See you next time.
[error: failed to close the database connection]

We have to decide whether farewell message should be printed or not, if close error occurs. You can address this in another PR.

[dcavalcante]

Addressed in 584a3e9. Cleanup now attempts to close the application, database client, and logger even if an earlier close fails, then returns all close errors with errors.Join. For the farewell behavior, I chose to preserve #110’s intent: if any cleanup step fails, no farewell is printed. Added tests for cleanup order, error aggregation, and farewell behavior.