Handle HTTP/1 remote disconnects

[samuel-williams-shopify]

Summary

• Treat Protocol::HTTP::RemoteError in the HTTP/1 server loop as a normal remote disconnect.
• Log the disconnect at debug level and terminate the affected connection.
• Close the response body with the original remote error.
• Continue to propagate unrelated exceptions such as raw application EPIPE failures.

Depends on socketry/protocol-http1#58, which maps connection-level EPIPE and ECONNRESET failures to Protocol::HTTP::RemoteError and prevents connection reuse.

Testing

• bundle exec bake test
• bundle exec rubocop
• bundle exec bake decode:index:coverage lib