feat: neofetch-style system info dump at startup

Prints DORF SYSTEM box to stdout before game loop begins:
OS, CPU (model + cores), GPU (WEBGPU_ADAPTER_NAME env var),
RAM total + free (from /proc/meminfo), display vsync mode,
initial chunk radius, world seed.

src/main.rs

@@ -13,10 +13,12 @@ mod constants;
 mod cursor;
 mod entities;
 mod game;
+mod system_info;
 mod world;
 
 fn main() {
     let game_config = config::GameConfig::load();
+    system_info::print_system_info(&game_config);
 
     App::new()
         .insert_resource(game_config)
@@ -29,6 +31,7 @@ fn main() {
                 .set(WindowPlugin {
                     primary_window: Some(Window {
                         title: String::from("Dorf"),
+                        present_mode: bevy::window::PresentMode::Mailbox,
                         ..Default::default()
                     }),
                     ..Default::default()