Serve grouped decode history payloads and restore each decoder through
explicit history restore hooks instead of replaying a mixed message stream.
This reduces replay overhead further by removing type regrouping and keeping
history restoration on decoder-specific bulk paths.
Co-authored-by: OpenAI Codex <codex@openai.com>
Signed-off-by: Stan Grams <sjg@haxx.space>
Serve a dedicated decode-history worker and move compressed history fetch
and CBOR parsing into that worker.
The main thread now drains ready-made decode batches within a frame budget,
which further reduces UI disruption during large history restores.
Co-authored-by: OpenAI Codex <codex@openai.com>
Signed-off-by: Stan Grams <sjg@haxx.space>