feat: enhance pre-push error handling and output reporting

[dbrosio3]

Description

Debugging with test repositories

Type of change

• fix: — Bug fix (patch version bump)
• feat: — New feature (minor version bump)
• feat!: / fix!: — Breaking change (major version bump)
• docs: — Documentation only (no version bump)
• chore: — Maintenance or config (no version bump)
• refactor: — Code restructure, no behaviour change (no version bump)

Changes made

• Improve error handling
• Improve output reporting

Testing

• pnpm test passes
• pnpm run check:shell passes with no output
• pnpm run lint:shell passes
• Manually tested the hook on a real repository
• Tested on macOS
• Tested on Linux

Checklist

• Commit messages follow Conventional Commits
• No eval, heredoc variable expansion, or unquoted variable interpolation in shell scripts
• File lists passed as arrays, never as interpolated strings
• VERSION, CHANGELOG.md, .release-please-manifest.json, and release-please-config.json were not manually edited — these are managed by release-please
• New template added to the table in README.md (if applicable)
• New template name added to install.sh usage comment (if applicable)

Screenshots / output