* fix: lower aiohttp keepalive timeout
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* fix(http): restore the 15s keep-alive default and apply it to the Rust client
15s is aiohttp's own default and what every release before v1.78.0 used. The Rust HTTP client reads the same AIOHTTP_KEEPALIVE_TIMEOUT variable, so its default moves with it.
* test(integration): cover upstream connections dropped after the keep-alive idle window
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Co-authored-by: nate <nate@berri.ai>
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
