Summary

• Replace git-hooks.flakeModule and treefmt-nix.flakeModule imports with direct lib usage
• Use treefmt-nix.lib.evalModule and git-hooks.lib.${system}.run directly
• Add formatter output for nix fmt support

Test plan

• nix flake check passes
• Pre-commit hooks still work (gitleaks, treefmt, ty)

Summary by cubic

Refactor Nix flake to remove git-hooks/treefmt flakeModule imports and use their libs directly. Adds a formatter output for nix fmt with no behavior change to formatting or hooks.

• Refactors

  • Use treefmt-nix.lib.evalModule and git-hooks.lib.${system}.run directly.
  • Expose formatter output and use the treefmt wrapper in hooks.
  • Switch devShell hook install to pre-commit-check.shellHook; keep gitleaks, treefmt, and ty.

• Dependencies

  • Update git-hooks.nix and treefmt-nix revisions in flake.lock.

^{Written for commit 17fc048. Summary will update on new commits.}