Docs: add get-lobby-status javadoc

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/lobby/get_lobby_status/GetLobbyStatusHandler.java

@@ -8,7 +8,14 @@ import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.ErrorRes
 import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
 import java.util.Optional;
 
-/** Handler for GET_LOBBY_STATUS: returns lobby details and player list. */
+/**
+ * Handler for the `GET_LOBBY_STATUS` command.
+ *
+ * <p>Resolves the target lobby either by the optional `ID` parameter or by `USERNAME`. If both are
+ * omitted the handler requires the session to be associated with a logged-in user (see the inline
+ * pre-execution check). On success a {@link GetLobbyStatusResponse} is dispatched, otherwise an
+ * {@link ErrorResponse} with code `LOBBY_NOT_FOUND` is sent.
+ */
 public class GetLobbyStatusHandler extends CommandHandler<GetLobbyStatusRequest> {
     private final LobbyManager lobbyManager;
     private final UserRegistry userRegistry;
@@ -46,10 +53,22 @@ public class GetLobbyStatusHandler extends CommandHandler<GetLobbyStatusRequest>
 
     @Override
     public void execute(GetLobbyStatusRequest request) {
+        // Resolve username from request or session when no explicit ID/USERNAME
+        // provided
+        String targetUsername = request.getUsername();
+        if (targetUsername == null) {
+            var maybeUser = userRegistry.getBySessionId(request.getSessionId());
+            if (maybeUser.isPresent()) {
+                targetUsername = maybeUser.get().getName();
+            }
+        }
+
         var lobby =
                 (request.getId() != null)
                         ? lobbyManager.getLobby(LobbyId.of(request.getId()))
-                        : lobbyManager.getLobbyByUsername(request.getUsername());
+                        : (targetUsername != null
+                                ? lobbyManager.getLobbyByUsername(targetUsername)
+                                : null);
 
         if (lobby == null) {
             responseDispatcher.dispatch(

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/lobby/get_lobby_status/GetLobbyStatusParser.java

@@ -5,6 +5,21 @@ import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Primitive
 import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.accessor.RequestParameterAccessor;
 
 public class GetLobbyStatusParser implements CommandParser<GetLobbyStatusRequest> {
+    /**
+     * Parse the incoming primitive request into a {@link GetLobbyStatusRequest}.
+     *
+     * <p>Supported optional parameters:
+     *
+     * <ul>
+     *   <li>`ID` (int) — numeric lobby id to query
+     *   <li>`USERNAME` (String) — username to lookup the lobby for
+     * </ul>
+     *
+     * If both are omitted the handler may require a logged-in session.
+     *
+     * @param primitiveRequest raw request containing parameters and context
+     * @return parsed {@link GetLobbyStatusRequest}
+     */
     @Override
     public GetLobbyStatusRequest parse(PrimitiveRequest primitiveRequest) {
         RequestParameterAccessor accessor =

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/lobby/get_lobby_status/GetLobbyStatusRequest.java

@@ -7,16 +7,25 @@ public class GetLobbyStatusRequest extends Request {
     private final Integer id;
     private final String username;
 
+    /**
+     * Create a new GetLobbyStatusRequest.
+     *
+     * @param context request context (session id, source, etc.)
+     * @param id optional numeric lobby id to query, or null
+     * @param username optional username to query the lobby for, or null
+     */
     public GetLobbyStatusRequest(RequestContext context, Integer id, String username) {
         super(context);
         this.id = id;
         this.username = username;
     }
 
+    /** Returns the optional lobby id. */
     public Integer getId() {
         return id;
     }
 
+    /** Returns the optional username. */
     public String getUsername() {
         return username;
     }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/lobby/get_lobby_status/GetLobbyStatusResponse.java

@@ -5,8 +5,19 @@ import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestCo
 import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.SuccessResponse;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.builder.ResponseBody;
 
-/** Response with lobby player listing and simple READY placeholders. */
+/**
+ * Success response for `GET_LOBBY_STATUS`.
+ *
+ * <p>Builds a response with a single `LOBBY` block containing `ID`, `NAME` and a nested `PLAYERS`
+ * collection with repeated `PLAYER` blocks (`USERNAME`, `READY`).
+ */
 public class GetLobbyStatusResponse extends SuccessResponse {
+    /**
+     * Create a new response for the provided {@link Lobby}.
+     *
+     * @param context request context to use for the response
+     * @param lobby lobby domain object containing id, name and players
+     */
     public GetLobbyStatusResponse(RequestContext context, Lobby lobby) {
         super(
                 context,