fix(docker): install node dependencies in init.sh

[palash018]

Closes #4845

Summary

bench init clones the Frappe app but does not install its Node dependencies. When bench start later launches the socketio service, it fails because socket.io is missing from apps/frappe/node_modules.

This PR ensures apps/frappe/node_modules is installed before bench start is reached, and that the script aborts if the installation fails.

Also includes small fixes in docker/init.sh:

• Corrects the shebang from #!bin/bash to #!/bin/bash.
• Adds exit 0 after the early "bench already exists" branch so the script does not fall through and attempt bench init again.
• Moves the NVM Node PATH export to the top so yarn is available in both the fresh-bench and existing-bench paths.

Changes

• docker/init.sh:
  • Install Node dependencies after bench init on fresh benches.
  • Install Node dependencies on existing benches before bench start.
  • Abort the script if yarn install fails so bench start never runs with missing dependencies.
  • Factor the install step into a helper so both call sites are consistent.
  • Fix shebang and prevent fall-through on existing bench.
  • Export NVM Node PATH before any yarn invocation.

Test plan

• Run docker compose down and docker compose up in the docker/ directory.
• Verify the frappe container completes initialization without Cannot find module 'socket.io' errors.
• Verify bench start launches web, socketio, schedule, and worker processes successfully.
• Verify the site is accessible at http://localhost:8000.

Generated with Devin

[greptile-apps]

Confidence Score: 5/5

This looks safe to merge.

• No blocking issues found in the changed code.

_{Reviews (5): Last reviewed commit: "fix(docker): export NVM PATH before any ..." | Re-trigger Greptile}