Add comprehensive CLI options for game settings

- Expanded `Cli` with arguments for username, game mode, map size, perk
  deck, resources, supply limit, XP modifier, and skill points limit.
- Enabled the `cli` module in `lib.rs` and activated argument parsing in
  `main.rs`.
- Added placeholder (commented) fields to `App` for future configuration
  integration.

src/cli.rs

@@ -2,7 +2,41 @@ use clap::Parser;
 
 #[derive(Parser, Debug)]
 #[command(version, about = "War in Tunnels", long_about = "War in Tunnels")]
-pub struct Cli {}
+pub struct Cli {
+    #[arg(long, help = "Username", value_name = "String")]
+    pub username: String,
+
+    #[arg(long, help = "Game mode", value_name = "LastManStanding or FrontLines")]
+    pub game_mode: String,
+
+    #[arg(long, help = "Map width", value_name = "Positive integer [20; 100]")]
+    pub map_width: u8,
+
+    #[arg(long, help = "Map height", value_name = "Positive integer [11; 50]")]
+    pub map_height: u8,
+
+    #[arg(long, help = "Perk Deck", value_name = "String (check Perk Deck tab)")]
+    pub perk_deck: String,
+
+    #[arg(long, help = "Starting wood", value_name = "Positive integer")]
+    pub starting_wood: u8,
+
+    #[arg(long, help = "Starting iron", value_name = "Positive integer")]
+    pub starting_iron: u8,
+
+    #[arg(long, help = "Supply limit", value_name = "Positive integer")]
+    pub supply_limit: u8,
+
+    #[arg(long, help = "XP modifier", value_name = "Float [0.5; 2.0]")]
+    pub xp_modifier: f32,
+
+    #[arg(
+        long,
+        help = "Skill points limit",
+        value_name = "Positive integer [120; 690]"
+    )]
+    pub skill_points_limit: u16,
+}
 
 pub fn get_args() -> Cli {
     Cli::parse()