Revert "Forward SIGTERM to children in Dockerfile CMD"

This reverts commit 1bd5e86.

The trap addition was incomplete. On the shutdown signal (Control
Plane sends SIGINT per docs.controlplane.com/reference/workload/termination.md),
the trap fires, `wait -n` returns 130, and `exit 1` then runs
unconditionally. The container exits with code 1 on every rolling
deploy instead of a code that reflects the signal-initiated shutdown.

More importantly, the trap was trying to solve a problem Control Plane
already handles. CP's default preStop hook runs `sh -c "sleep 45"`
before any signal reaches PID 1, and the sidecar stops accepting new
inbound connections ~80 seconds ahead of termination. That sleep plus
the routing drain is the graceful-shutdown window; signal forwarding
inside the container is marginal on top of it.

Match the reference deployments verbatim: the react-on-rails-demo-
marketplace-rsc Dockerfile and the hichee production Dockerfile both
use this exact bash-c pattern without a trap. If deeper graceful
shutdown is ever needed, the right tool is extending preStop or
switching to a process manager (overmind, tini), not a bash trap on
wait -n.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: ihabadham

.controlplane/Dockerfile

@@ -83,8 +83,5 @@ ENTRYPOINT ["./.controlplane/entrypoint.sh"]
 # Run the Pro Node renderer and Rails in a single container (Option 1 from
 # docs/oss/building-features/node-renderer/container-deployment.md).
 # `wait -n` exits on first child failure → container exits → Control Plane
-# restarts the whole unit. The trap forwards SIGTERM/SIGINT to both children
-# so rolling deploys can drain: Puma and the renderer's cluster manager both
-# handle SIGTERM, but bash as PID 1 doesn't forward the signal by default.
-# Keeps the existing Thruster HTTP/2 proxy for Rails.
-CMD ["bash", "-c", "node renderer/node-renderer.js & RENDERER_PID=$! ; bundle exec thrust bin/rails server & RAILS_PID=$! ; trap 'kill -TERM $RENDERER_PID $RAILS_PID' TERM INT ; wait -n ; exit 1"]
+# restarts the whole unit. Keeps the existing Thruster HTTP/2 proxy for Rails.
+CMD ["bash", "-c", "node renderer/node-renderer.js & RENDERER_PID=$! ; bundle exec thrust bin/rails server & RAILS_PID=$! ; wait -n ; exit 1"]