Add the localization/ directory to the Flatpak source list so
run_gettext.sh can compile .po files into .mo translations.
Replace LC_ALL=C.UTF-8 with LC_NUMERIC=C in the entrypoint script
to preserve the user's language settings while still preventing
decimal-separator parsing issues.
Move many third-party components' source codes from the src folder to a new folder called deps_src. The goal is to make the code structure clearer and easier to navigate.