⚡ Optimize file reading in artifacts router using aiofiles

[miethe]

Replaced synchronous open() calls with asynchronous aiofiles.open() in get_artifact_file_content to prevent blocking the event loop. Updated is_binary_file helper to be asynchronous as well. Verified with tests and latency benchmark.

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PR created automatically by Jules for task 10003914473512412869 started by @miethe

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