Summary

Add a new config field max_merged_line_bytes which allows limiting maximum line size even when auto_partial_merge is enabled (see #22581).

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

How did you test this PR?

Added unit tests to exercise the new configuration.

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the "no-changelog" label to this PR.

Checklist

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References

• Closes: kubernetes_logs source permits arbitrarily large lines due to interaction of auto_partial_merge and max_line_bytes #22581