fix: rm redundant emission to $HOME/.pm2/logs (#1640)

Override the pm2 daemon's emission of `logs/unraid-api-{out,error}.log`,
which is a duplicate of the stdout appended to
`/var/log/graphql-api.log`.

Correctly implements the sane interpretation of what the `log_file`
configuration does.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Chores**
* Improved process logging by separating standard output and error
streams while supporting merged logs when multiple sources are present.
* Enhances log clarity and troubleshooting without changing application
behavior.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

api/ecosystem.config.json

@@ -13,7 +13,9 @@
             "watch": false,
             "interpreter": "/usr/local/bin/node",
             "ignore_watch": ["node_modules", "src", ".env.*", "myservers.cfg"],
-            "log_file": "/var/log/graphql-api.log",
+            "out_file": "/var/log/graphql-api.log",
+            "error_file": "/var/log/graphql-api.log",
+            "merge_logs": true,
             "kill_timeout": 10000
         }
     ]