Add debug logging for metrics collection failures

[rishh09]

Fixes #649

What this PR does

Adds debug logging for metrics collection failures that were previously silently ignored.

The debug namespaces are scoped by metric area, for example:

• prom:metrics:gc
• prom:metrics:event-loop-lag
• prom:metrics:process-open-fds
• prom:metrics:process-max-fds

This keeps the default behavior quiet, while allowing users to inspect these failure paths with DEBUG=prom:*.

Notes

debug is moved from devDependencies to dependencies because it is now required by runtime library files.

Tests

• npm run lint
• npm run check-prettier
• npm run compile-typescript
• npm run test-unit -- --runInBand --forceExit
• npm test -- --runInBand --forceExit

[rishh09]

Hi @jdmarshall, I opened this PR for #649 based on your latest comment about adding debug output to empty catch blocks.

I wasn’t able to add you as a reviewer directly, so tagging you here for visibility. Happy to adjust the namespace or message style if you prefer a different convention.

[jdmarshall]

As @zbjornson recommended, please migrate to the Node native debug logging found in node:util

[jdmarshall]

@rishh09 If you would be so kind, would you mind fixing

client_js/benchmarks/index.js

Line 18 in 4339b07

const debug = require('debug')('benchmark');

while you're in here so we can remove debug entirely?

I'm thinking back to #708 and the fact that the benchmarks run as a CI action and maybe we should just not...

[rishh09]

sure, I'll proceed with these recommended changes and push a commit.

[jdmarshall]

This one deserves a Changelog entry under additions: support for debug messages