- Introduce `docs/kge.1` and `docs/kte.1` man pages covering usage, options, keybindings, and examples.
- Update `CMakeLists.txt` to install man pages under `${CMAKE_INSTALL_MANDIR}/man1`.
- Ensure `kge` man page installation is conditional on GUI being built.
- Document `TestFrontend` for programmatic testing, including examples and usage details.
- Add `UpdateBufferReference` to `UndoSystem` to support updating buffer associations.