feat: add Unity/Godot WebSocket server (Phase 1 stub)

- pom.xml: add Java-WebSocket 1.5.6 dependency
- bridge/GameWsServer.java: WS server on ws://localhost:7654
- bridge/GameSession.java: Phase 1 stub game loop with human-input queue
- cli/LabCli.java: add ws-server subcommand via picocli

src/main/java/commanderailab/cli/WsServerCommand.java

@@ -0,0 +1,62 @@
+package commanderailab.cli;
+
+import commanderailab.bridge.GameWsServer;
+import picocli.CommandLine.Command;
+import picocli.CommandLine.Option;
+
+import java.util.concurrent.Callable;
+
+/**
+ * WsServerCommand — picocli subcommand that starts the interactive game WebSocket server.
+ *
+ * Usage:
+ *   java -jar commander-ai-lab.jar ws-server \
+ *     --forge-jar path/to/forge.jar \
+ *     --forge-dir path/to/forge-gui \
+ *     --port 7654
+ *
+ * Then connect Unity/Godot to ws://localhost:7654 and send:
+ *   { "type": "START_GAME", "decks": ["DeckA","DeckB","DeckC","DeckD"], "seed": 42 }
+ */
+@Command(
+    name = "ws-server",
+    mixinStandardHelpOptions = true,
+    description = "Start the interactive game WebSocket server for Unity/Godot clients."
+)
+public class WsServerCommand implements Callable<Integer> {
+
+    @Option(names = {"--forge-jar", "-F"}, required = true,
+            description = "Path to Forge desktop JAR (forge-gui-desktop-XXX-jar-with-dependencies.jar)")
+    private String forgeJarPath;
+
+    @Option(names = {"--forge-dir", "-W"}, required = true,
+            description = "Forge working directory (folder containing res/)")
+    private String forgeWorkDir;
+
+    @Option(names = {"--port", "-p"}, defaultValue = "7654",
+            description = "WebSocket port (default: 7654)")
+    private int port;
+
+    @Override
+    public Integer call() throws Exception {
+        System.out.println("╔══════════════════════════════════════════════════╗");
+        System.out.println("║    Commander AI Lab — Interactive WS Server      ║");
+        System.out.println("╚══════════════════════════════════════════════════╝");
+        System.out.println();
+        System.out.println("  Forge JAR : " + forgeJarPath);
+        System.out.println("  Forge Dir : " + forgeWorkDir);
+        System.out.println("  WS Port   : " + port);
+        System.out.println();
+
+        GameWsServer server = new GameWsServer(port, forgeJarPath, forgeWorkDir);
+        server.start();
+
+        System.out.println("  Ready — connect Unity/Godot to ws://localhost:" + port);
+        System.out.println("  Press Ctrl+C to stop.");
+        System.out.println();
+
+        // Block until killed
+        Thread.currentThread().join();
+        return 0;
+    }
+}