apply_configs can hang forever in cli_progress at ~94% CPU with no child processes — configs are already applied, wrapper never exits

Describe the bug

apply_configs (CLI, over SSH) sometimes never returns. The python -m cli_progress wrapper process spins at ~90–95% CPU with no child processes under it. All configs are in fact already applied — the hang is purely in the progress-display layer. Killing the wrapper is safe.

Root cause pointer

common/utils.sh (~line 446) wraps the whole installer:

python -m cli_progress --title "Hiddify Manager" "$@"

Observed on 12.3.3 / Ubuntu 24.04: the wrapper busy-loops with no children for tens of minutes after the underlying work is done. I have not traced it further into cli_progress internals — reporting as observed. Possibly related to terminal-state detection when there is no interactive TTY (no usable $TERM / terminal width over a plain SSH exec), but that is a hypothesis, not a verified cause.

The practical damage: users see a stuck "applying" screen, conclude the apply failed, and start a second apply concurrently (see also the lock-related behavior in install.sh) or abandon the box mid-way — while the config is actually fine.

To Reproduce

Not yet deterministic on demand; happened repeatedly on this setup during DNSTT-related applies over SSH (ssh host /opt/hiddify-manager/apply_configs.sh).

1. Run apply_configs from a non-interactive SSH session.
2. Occasionally: wrapper stays alive forever at ~94% CPU, ps --ppid <pid> shows nothing.
3. Configs and services are in their target state.

Expected behavior

The progress wrapper must exit when the wrapped pipeline is done, and must never busy-loop without children.

Environment

• Hiddify Manager: 12.3.3
• OS: Ubuntu 24.04, kernel 6.8
• Invocation: apply_configs over SSH, non-interactive

Suggested directions

• Fall back to plain passthrough logging when no interactive TTY is detected.
• Add a watchdog inside the wrapper (exit when the child pipeline is gone).
• On pipeline completion, flush and exit instead of continuing to animate.

Workaround for users

timeout 600 /opt/hiddify-manager/apply_configs.sh

then verify by inspecting services/configs rather than trusting the progress bar. A hung wrapper can be killed safely — the install itself has already completed.