app/vlinsert/opentelemetry: fix field collisions after flattening

[yagmurcicekdagi]

Changes

Fixes: #1371

• Added -opentelemetry.enableFieldPrefixes flag (disabled by default). When enabled, fields are prefixed
  by their source before flattening:

  resource.attributes[\"service.name\"] -> resource.service.name
  logRecord.attributes[\"service.name\"] -> attributes.service.name
  logRecord.body (KV list) [\"service.name\"] -> body.service.name

• Added tests covering prefix mode for all field sources and verify generated fields
  (trace_id, span_id, severity_number, severity_text) remain unprefixed.

• Updated docs/victorialogs/data-ingestion/opentelemetry.md with a Field prefixes
  section and victoria_logs_common_flags.md with the new flag.

[cubic-dev-ai]

No issues found across 6 files

[yagmurcicekdagi]

Hi, Can you review this pr ? @func25? I've fixed the field name collisions, haven't implemented the query/merge path duplicate name issue yet. Let me know what you think so I can adjust the code.

[func25]

Hey, thank you for your interest in this issue.

haven't implemented the query/merge path duplicate name issue yet

I'd recommend starting with a few smaller issues first to get familiar with the logic, the code conventions and the contribution guidelines. As I skimmed through it, this PR appears to be a low-quality AI-generated contribution.

[yagmurcicekdagi]

I did use AI to help me locate the issue and give me skeleton to work on, but if you mean the abstractions that I put , that was from me unfortunately -which breaks the contribution guidelines

Could you maybe guide me a bit to how to make this code better quality?

I'd still love to work on getting this to better quality code, but if you don't want that, that's totally understandable as well

Thanks for the reply @func25

[func25]

No problem. I saw some improvements/bug fixes in this PR itself, it's not entirely AI-generated slop, so haven't closed it. Please see below comments.

Using AI to enhance quality and make small improvements is encouraged, but not for this kind of task (yet).

[func25]

Hey @yagmurcicekdagi, any updates?

[yagmurcicekdagi]

Hey, I've updated the code @func25