#296 fix(init): document and uninstall managed hooks

Summary

• Document that init --install-hook installs both prepare-commit-msg and post-commit hooks.
• Print the full path of each installed hook.
• Add reversible init --uninstall-hook support that restores existing hooks and preserves user replacements.
• Add regression coverage for installation, repeated installation, restoration, removal, and user-hook protection.

Fixes #278

Issue: https://github.com/404-PF/commit-echo/issues/278

Testing

• npm run build
• npx tsc --noEmit
• npm run format:check
• npm test (369 passed, 4 skipped; the 2 pre-existing failures also reproduce on main)