When using git commit --amend gptcommit always replaces the last commit message with the same generic message:

# AI Generated Commit Summary:
# EDIT BELOW AS NEEDED
- Refactor backend code to improve performance
- Update frontend design to improve user experience
- Add new features to improve application functionality
#
# File-level changes:
~                      

error[E0433]: failed to resolve: could not find `unix` in `os`
 --> C:\Users\mk\scoop\persist\rustup-msvc\.cargo\registry\src\github.com-1ecc6299db9ec823\gptcommit-0.1.0\src\actions\install.rs:4:27
  |
4 |     process::Command, os::unix::prelude::PermissionsExt,
  |                           ^^^^ could not find `unix` in `os`

error[E0599]: no function or associated item named `from_mode` found for struct `Permissions` in the current scope
  --> C:\Users\mk\scoop\persist\rustup-msvc\.cargo\registry\src\github.com-1ecc6299db9ec823\gptcommit-0.1.0\src\actions\install.rs:45:64
   |
45 |     fs::set_permissions(&prepare_commit_msg_path, Permissions::from_mode(0o755))?;
   |                                                                ^^^^^^^^^ function or associated item not found in `Permissions`

Some errors have detailed explanations: E0433, E0599.
For more information about an error, try `rustc --explain E0433`.
error: could not compile `gptcommit` due to 2 previous errors
error: failed to compile `gptcommit v0.1.0`, intermediate artifacts can be found at `C:\Users\mk\AppData\Local\Temp\cargo-installdYv1GZ`

[src/actions/install.rs]

• Add #[cfg(unix)] annotation for the permissions setter
• Set the permissions for the prepare-commit-msg file to 0o755 on unix only

refs #1

• Switch to colored output and remove unnecessary dependencies
• Reduce maximum length of summary comments
• Add installation options and demo link to README