Ensure connection is closed when raw SSE stream raises

[jsxs0]

Summary

Add an ensure block to SSE::Application#start_raw_stream so the Iodine connection is always closed if the user's Proc raises an exception without calling close.

Problem

start_formatted_stream (Enumerator path) has ensure connection.close — the connection always cleans up, even on exception. start_raw_stream (Proc path) does not — if the Proc raises before calling connection.close, the connection leaks until Iodine's socket timeout.

# Has ensure — connection always closed
def start_formatted_stream(connection)
  @stream.each { |event| ... }
ensure
  connection.close
end

# Missing ensure — connection leaks on exception
def start_raw_stream(connection)
  @stream.call(Rage::SSE::ConnectionProxy.new(connection))
end

Fix

def start_raw_stream(connection)
  @stream.call(Rage::SSE::ConnectionProxy.new(connection))
ensure
  connection.close if connection.open?
end

The connection.open? guard avoids double-closing when the Proc already called close.

Test plan

• Added spec/sse/application_spec.rb with 3 test cases:
  • Proc raises → connection closed
  • Proc closes normally → no double-close
  • Proc forgets to close → connection still closed
• bundle exec rspec spec/sse/ — 47 examples, 0 failures