Extracted common quit/esc handling into `common_keybindings`. Introduced
`Group::CtrlMovement` for Ctrl‑arrow keys and updated keybinding
definitions.
Removed duplicated quit logic in main_menu and skirmish modules. Bumped
clap to 4.6.0 and updated Cargo.lock. Added range‑checked parsers for
map
size, resources, supply limit, XP modifier and skill points in the CLI.