Complete Stage 1: Core Game Loop

- Add GameState enum (LOBBY, ROLE_ASSIGN, IN_GAME, ENDING)
- Add Phase interface with enter/tick/exit/isComplete
- Add GameSession with tick-based phase machine
- Add GameEventBus for internal events
- Add GameManager for session lifecycle
- Add all phases: LobbyPhase, RoleAssignPhase, GameplayPhase, EndgamePhase
- Add role assignment: RoleAssigner, RoleQueue, SpawnPosition
- Add BasePlayer, Survivor, Killer, PlayerState
- Add DBDCommand with /dbd join/leave/create/forcestart/stop
- Update mdbd.java with GameManager and command registration
- Add command definition to paper-plugin.yml
- Mark Stage 1 complete in PLAN.md

src/main/java/dev/loki/phase/LobbyPhase.java

@@ -0,0 +1,74 @@
+package dev.loki.phase;
+
+import dev.loki.config.GameConfig;
+import dev.loki.core.GameSession;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.format.NamedTextColor;
+import org.bukkit.Bukkit;
+
+public class LobbyPhase implements Phase {
+    private final GameConfig config;
+    private int countdown;
+    private int secondsLeft;
+    private boolean started;
+
+    public LobbyPhase(GameConfig config) {
+        this.config = config;
+        this.secondsLeft = config.getLobbyCountdown();
+        this.countdown = 0;
+        this.started = false;
+    }
+
+    @Override
+    public void enter(GameSession session) {
+        Bukkit.broadcast(Component.text("[DBD] Лобби открыто! Используйте /dbd join", NamedTextColor.GREEN));
+    }
+
+    @Override
+    public void tick(GameSession session) {
+        int playerCount = session.getPlayerCount();
+        int minPlayers = config.getMinPlayers();
+
+        if (playerCount < minPlayers) {
+            secondsLeft = config.getLobbyCountdown();
+            countdown = 0;
+            started = false;
+            return;
+        }
+
+        countdown++;
+        if (countdown >= 20) {
+            countdown = 0;
+            secondsLeft--;
+
+            if (secondsLeft <= 5 || secondsLeft % 10 == 0) {
+                Bukkit.broadcast(Component.text(
+                    "[DBD] До начала: " + secondsLeft + " сек. (" + playerCount + "/" + minPlayers + ")",
+                    NamedTextColor.YELLOW));
+            }
+        }
+
+        if (secondsLeft <= 0) {
+            started = true;
+        }
+    }
+
+    @Override
+    public void exit(GameSession session) {
+        Bukkit.broadcast(Component.text("[DBD] Игра начинается!", NamedTextColor.GREEN));
+    }
+
+    @Override
+    public boolean isComplete() {
+        return started;
+    }
+
+    public void forceStart() {
+        secondsLeft = 0;
+        started = true;
+    }
+
+    public int getSecondsLeft() {
+        return secondsLeft;
+    }
+}