feat(prysm): add prysmctl & client‑stats binaries + systemd service

Summary

This PR extends the Prysm update flow in update_consensus.sh to also download and install the prysmctl and client‑stats binaries, and to stop/restart a new client‑stats systemd service alongside the existing consensus and validator services. It also adds:

• client-stats.service – a systemd unit for running the Prysm client‑stats exporter
• install_client_stats_service.sh – an install script to deploy & enable that service

What’s Changed

1. update_consensus.sh (Prysm case)

   • Added two new download targets:

     file_client_stats=client-stats-${prysm_version}-${_platform}-${_arch}
     file_prysmctl=prysmctl-${prysm_version}-${_platform}-${_arch}

   • Download both with curl -f -L … and make them executable:

     curl -f -L "https://prysmaticlabs.com/releases/${file_client_stats}" -o client-stats
     curl -f -L "https://prysmaticlabs.com/releases/${file_prysmctl}"     -o prysmctl
     chmod +x client-stats prysmctl

   • Stop/start the client‑stats service in line with consensus & validator:

     sudo systemctl stop client-stats   # before removal/install
     …
     sudo systemctl start client-stats  # after moving binaries

2. New file: client-stats.service

   [Unit]
   Description=Prysm Client Stats
   Wants=network-online.target
   After=network-online.target
   Requires=validator.service
   
   [Service]
   Type=simple
   User=prysm
   Group=prysm
   Restart=on-failure
   RestartSec=3
   KillSignal=SIGINT
   TimeoutStopSec=900
   ExecStart=/usr/local/bin/client-stats \
     --beacon-node-metrics-url=http://localhost:8080/metrics \
     --validator-metrics-url=http://localhost:8081/metrics \
     --clientstats-api-url=https://beaconcha.in/api/v1/stats/<YOUR_BEACONCHA.IN_API-KEY>/<YOUR_VALIDATOR_NAME> \
     --scrape-interval 3m
   
   [Install]
   WantedBy=multi-user.target
   
   

3. New file: install_client_stats_service.sh

#!/bin/bash

# Copy the service file to systemd directory
sudo cp client-stats.service /etc/systemd/system/

# Reload systemd to recognize the new service
sudo systemctl daemon-reload

# Enable the service to start on boot
sudo systemctl enable client-stats

# Start the service
sudo systemctl start client-stats

echo "Prysm client-stats service has been installed and started."

Testing & Verification

1. Run the update script for Prysm:

./update_consensus.sh Prysm

2. Confirm the new binaries exist and are executable:

ls -l /usr/local/bin/{prysmctl,client-stats}

3. Verify the client-stats service status:

sudo systemctl status client-stats

• Service should be loaded, enabled, and running without errors.

4. (Optional) Tail the logs to confirm metrics scraping and API uploads:

sudo journalctl -u client-stats -f