Feature: dynamic command discovery for JSON-RPC and enhanced testing

src/jsonrpc.rs

@@ -126,12 +126,7 @@ async fn handle_request(
             }
         },
         "list_commands" => {
-            json!([
-                "look", "go", "north", "south", "east", "west", "up", "down",
-                "say", "who", "take", "drop", "inventory", "equip", "use",
-                "examine", "talk", "attack", "defend", "flee", "cast",
-                "spells", "skills", "guild", "stats", "help"
-            ])
+            json!(commands::get_command_list())
         },
         "execute" => {
             if let Some(pid) = *current_player_id {