The side-task creation route still constructed a session service directly on
two rollback paths after the surrounding module moved to the workspace runtime
helper, leaving the identifier unbound and breaking the CLI build on main.
Route both rollbacks through the workspace runtime helper so they honour the
per-workspace runtime base dir like every other session-service use in this
module.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>