ensureGitRepositoryForProjectPath unconditionally ran `git init` on
non-git paths, including workspace roots. This created a stray empty
repo with unborn HEAD at the workspace root, poisoning every downstream
git command (executor session cwd: `fatal: ambiguous argument 'HEAD'`).
Add an early-return guard that checks loadWorkspaceConfig before any git
operation, keeping the workspace root non-git as intended by the
workspace execution contract.
a9ea1f6fe3