fix(server): refine error handling and PM2 connection logic

- Reduced the maximum restarts for PM2 processes from 20 to 8 and added a restart delay of 2000ms for better stability.
- Improved error handling during server startup and PM2 connection, ensuring clearer logging and graceful exits on failure.
- Introduced a utility function to filter out PM2 metadata from environment variables, preventing conflicts during process management.

ecosystem.config.cjs

@@ -48,7 +48,8 @@ module.exports = {
       instances: 1,
       exec_mode: "fork",
       autorestart: true,
-      max_restarts: 20,
+      max_restarts: 8,
+      restart_delay: 2000,
       env: {
         ...env,
         JFLOW_CONTROL_PORT: env.JFLOW_CONTROL_PORT ?? "8600",