[Cherry-pick to release/v0.5.20] [gRPC] Stream engine state changes (#39915) - #40137

[Cherry-pick to release/v0.5.20] [gRPC] Stream engine state changes (#39915)#40137

Qiaolin-Yu merged 1 commit into

release/v0.5.20sgl-project/sglang:release/v0.5.20from

cherry-pick/0214954f26-to-v0.5.20-af29fc11sgl-project/sglang:cherry-pick/0214954f26-to-v0.5.20-af29fc11Copy head branch name to clipboard