[BUG] cog commit fails on Windows with os error 193 when any git hook is installed (including hooks installed by cog itself)

[tropfzahn]

Description

cog commit fails on Windows with os error 193 whenever a git hook is
installed — including hooks installed by Cocogitto itself via
cog install-hook. This breaks Cocogitto's own documented functionality
on Windows.

Environment

• OS: Windows (PowerShell)
• Cocogitto version: 7.0.0

Minimal reproduction (no third-party tools needed)

1. Add a hook to cog.toml exactly as shown in the official documentation:

   [git_hooks.commit-msg]
   script = """#!/bin/sh
   echo "hook works"
   """

2. Install the hook:

   cog install-hook commit-msg

3. Run:

   cog commit feat "my message"

Actual behavior

Error: IO Error
cause: %1 ist keine zulässige Win32-Anwendung. (os error 193)

Expected behavior

cog commit executes successfully.

Additional reproduction (third-party hook managers)

The same error occurs when hooks are installed by any external tool such as
Lefthook. The content of the hook is irrelevant — the error appears as soon
as any shell script exists in .git/hooks/.

Root cause analysis

Cocogitto installs hooks as shell scripts with a #!/bin/sh shebang.
When executing them, it calls the hook directly via Rust's
std::process::Command without invoking a shell. Windows cannot execute
shebang-based shell scripts as direct processes, resulting in
os error 193 (ERROR_BAD_EXE_FORMAT).

git commit does not have this problem because Git for Windows delegates
hook execution to its bundled sh.exe.

Cocogitto therefore installs hooks that it cannot execute on Windows —
breaking its own documented functionality.

Suggested fix

On Windows, resolve sh.exe from the Git installation and use it to
execute hook scripts, mirroring how Git itself handles hook execution:

// Instead of:
Command::new(hook_path)

// On Windows:
Command::new("sh").arg(hook_path)

The sh.exe path can be resolved dynamically, e.g. via git --exec-path
or by locating the Git for Windows installation directory.