impl/17-issue-assigned-git-steps
main
改动 1: issue_assigned 编码路径 steps 改为具体 git 命令 (checkout main → pull → checkout -b → add/commit → push) 改动 2: ToolchainApiSection 新增 Git 操作说明段落(含开发目录路径) 改动 3: 测试更新(issue_assigned 断言 + 3 个 Git 说明测试) 466 passed