Fix systemd service startup hang (#72)

[y-vectorfield]

Description

Fixes #72

Problem

systemctl restart pironman5.service hangs on Ubuntu 24.04 (Noble Numbat)
due to After=multi-user.target causing global startup transaction deadlock.

Changes

• Change After=multi-user.target to After=network-online.target
  to prevent global startup transaction deadlock
• Change Type=simple to properly manage long-running process
  with child processes (influxd, dbus-daemon)
• Add Restart=on-failure for automatic recovery on failure
• Add StandardOutput/StandardError=journal for better logging

Testing

Verified on Ubuntu 24.04 LTS with:

• systemctl restart pironman5.service completes successfully
• Service becomes active (running) with expected child processes
• Child processes (influxd, dbus-daemon) properly managed by systemd

[y-vectorfield]

@cavonlee , please review my PR. If there are not any problems, please approve and merge my modifications.

[y-vectorfield]

@kyuuinochi , please review my PR. If there are not any problems, please approve and merge my modifications.