refactor(sdk)!: StreamingDeltaEvent stops subclassing Event and gets its own fan-out @calm-artist-7206 🙂 Moreover another small one: perf(sdk): make EventLog.append cost flat against conversation length

I actually started reading them, sorry taking a look

don't worry

Left a silly comment. I really appreciate you digging into this whole thing. I think maybe it was overdue tbh ❤️