Skip failed TRX attachment copies

[Copilot]

A missing or inaccessible test attachment could abort TRX generation for the entire run. Attachment copy failures should be reported without dropping otherwise valid test results.

• Attachment copy handling

  • Catch per-attachment IOException and UnauthorizedAccessException.
  • Skip only the failed attachment.
  • Continue copying remaining attachments and generating the TRX.

• TRX warning output

  • Add RunInfo warning entries for skipped attachments.
  • Reuse the RunInfo path for crash/exit-code messages.

• Regression coverage

  • Added a test covering one failed per-test attachment copy while another attachment is still emitted.

<RunInfo outcome="Warning">
  <Text>Unable to copy attachment '...' into the TRX results directory. The attachment will be skipped. Reason: UnauthorizedAccessException.</Text>
</RunInfo>