Populate /role_scripts/standby for remote replica coordinator

[souravbiswassanto]

Summary

• In init_scripts/run.sh, the REMOTE_REPLICA=true branch now also copies standby scripts into /role_scripts/standby/ in addition to /run_scripts/role/

Problem

The pg-coordinator's AddRoleBasedScripts() restores postgres startup scripts after a crash by copying from /role_scripts/<raftRole>/ (e.g. /role_scripts/standby/). For HA clusters the init container populates this directory, but for remote replicas it only populated /run_scripts/role/ and left /role_scripts/ empty. This caused AddRoleBasedScripts() to silently fail, leaving postgres unable to restart after recovery.

Test plan

• Deploy a remote replica with the new pg-coordinator (remote replica mode)
• Trigger a recovery scenario (timeline divergence)
• Verify the coordinator can successfully call AddRoleBasedScripts() and postgres restarts with the correct standby scripts