[wip] brotli

[JennyPng]

copilot's brotli attempt

1. started from assumptions.md
2. broke task into 3 subitems (refactor, add brotli decompress, add brotli support in streaming)
3. wrote research.md files for each subitem
4. wrote 3 separate plan md files for each subitem. evaluated plans and documented it in gao documents, and then applied critiques back onto the plan
5. implemented and wrote an execution log for each subitem plan