Local-install managed .sh hooks under Claude Code on Windows were wrapped with the absolute Git Bash path; Claude runs the hook string inside Git Bash, so bash tried to exec bash (cannot execute binary file). Centralizes the win32+claude+.sh guard (shellHookOmitsBashRunner) and adds an exported, testable buildLocalShellHookCommand so the local path matches the global path. Closes the #166/#377 regression in the local-install branch. Adds a Windows-covered regression test.
Fixes#580