fix: fix potential memory leaks

Merge pull request #826 from ch4og/guix-fixes

fix(guix): pin wlroots version

feat(nix): add build-time configuration validation

feat(nix): support old config format with deprecation warning

feat(nix): add keymode support for modal keybindings

refactor(nix): add structured config support to home-manager module

opt: optimize foreign toplevel state sync

Merge pull request #814 from atheeq-rhxn/docs-update

bump version to 0.12.8

docs: update pikaos installation

opt: always notify the position change to x11 client

opt: dont force request resize when the x11 app reject resize

break: rename force_maximize to force_fakemaximize

docs: add scroll_button desc