The Desktop serve backend polls /api/fs/default-cwd, whose git-branch probe
captured git output with text=True and no encoding. subprocess then decodes
with locale.getencoding() - cp936 on zh-CN Windows - so a UTF-8 branch name or
git's localized stderr raised UnicodeDecodeError inside communicate()'s
_readerthread on every poll ([gateway-crash] ... 'gbk' codec can't decode).
Pin encoding='utf-8', errors='replace' on the remaining in-process captures
whose children emit UTF-8: the git branch probe, the self-repo guard's git
alias read, the Bot Mode DM transport (a Hermes CLI child, stdio forced to
UTF-8; builds on the salvaged errors='replace'), the agent-browser npx probe,
the lightpanda help probe, and the cua-driver stderr drain thread.
Fixes#83851
0a0e6334c6