Jianhui Zhao 2489b605a7 Remove log file fallback for non-TTY output ...

The feature that wrote logs to a file when stdout wasn't a terminal is
removed. Systemd services already handle log persistence through journald
and its logging facilities. This duplication is unnecessary and conflicts
with standard systemd logging practices.

View log in systemd:

```
journalctl -u rttys
```

or

```
journalctl -u rttys -f
```

Signed-off-by: Jianhui Zhao <zhaojh329@gmail.com>

2025-07-29 14:55:29 +08:00

..

log.go

Remove log file fallback for non-TTY output

2025-07-29 14:55:29 +08:00