SIGTERM was being ignored by child processes. Use SIGKILL via the
actual process group ID, with proc.kill() as fallback.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Start CLI subprocesses in their own session so SIGTERM via
os.killpg reaches child processes (rsync, etc.) not just the shell.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Backup and restore operations now run as background jobs instead of
blocking modal screens. Users can navigate away and check progress
from a dedicated Running Tasks screen. OperationLog supports attaching
to running jobs with live output polling.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
