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]

Since this library is only used within other tools, should this be a dep or a peer dependency? @SimenB @zbjornson