Complete Stage 0: Project scaffold

- Fix build.gradle.kts: Java 21, Paper 1.20.6, ProtocolLib 5.3.0
- Add permissions to paper-plugin.yml
- Add ConfigManager with safe yaml loading (no overwrite)
- Add LocationsConfig for all game object coordinates
- Add GameConfig with all balance values
- Update mdbd.java with onEnable/onDisable + ConfigManager
- Mark Stage 0 complete in PLAN.md

src/main/java/dev/loki/config/LocationsConfig.java

@@ -0,0 +1,159 @@
+package dev.loki.config;
+
+import org.bukkit.Bukkit;
+import org.bukkit.Location;
+import org.bukkit.World;
+import org.bukkit.configuration.file.FileConfiguration;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class LocationsConfig {
+    private final FileConfiguration config;
+
+    public LocationsConfig(FileConfiguration config) {
+        this.config = config;
+        setDefaults();
+    }
+
+    private void setDefaults() {
+        if (!config.contains("lobby")) {
+            config.set("lobby.world", "world");
+            config.set("lobby.x", 0.0);
+            config.set("lobby.y", 100.0);
+            config.set("lobby.z", 0.0);
+            config.set("lobby.yaw", 0.0);
+            config.set("lobby.pitch", 0.0);
+        }
+        if (!config.contains("generators")) {
+            config.set("generators", new ArrayList<>());
+        }
+        if (!config.contains("hooks")) {
+            config.set("hooks", new ArrayList<>());
+        }
+        if (!config.contains("pallets")) {
+            config.set("pallets", new ArrayList<>());
+        }
+        if (!config.contains("windows")) {
+            config.set("windows", new ArrayList<>());
+        }
+        if (!config.contains("chests")) {
+            config.set("chests", new ArrayList<>());
+        }
+        if (!config.contains("totems")) {
+            config.set("totems", new ArrayList<>());
+        }
+        if (!config.contains("exitgates")) {
+            config.set("exitgates", new ArrayList<>());
+        }
+        if (!config.contains("killer-spawn")) {
+            config.set("killer-spawn", new ArrayList<>());
+        }
+        if (!config.contains("survivor-spawns")) {
+            config.set("survivor-spawns", new ArrayList<>());
+        }
+    }
+
+    public Location getLobby() {
+        World world = Bukkit.getWorld(config.getString("lobby.world", "world"));
+        if (world == null) return null;
+        return new Location(
+            world,
+            config.getDouble("lobby.x", 0.0),
+            config.getDouble("lobby.y", 100.0),
+            config.getDouble("lobby.z", 0.0),
+            (float) config.getDouble("lobby.yaw", 0.0),
+            (float) config.getDouble("lobby.pitch", 0.0)
+        );
+    }
+
+    public void setLobby(Location loc) {
+        config.set("lobby.world", loc.getWorld().getName());
+        config.set("lobby.x", loc.getX());
+        config.set("lobby.y", loc.getY());
+        config.set("lobby.z", loc.getZ());
+        config.set("lobby.yaw", loc.getYaw());
+        config.set("lobby.pitch", loc.getPitch());
+    }
+
+    public List<Location> getGenerators() {
+        return loadLocationList("generators");
+    }
+
+    public List<Location> getHooks() {
+        return loadLocationList("hooks");
+    }
+
+    public List<Location> getPallets() {
+        return loadLocationList("pallets");
+    }
+
+    public List<Location> getWindows() {
+        return loadLocationList("windows");
+    }
+
+    public List<Location> getChests() {
+        return loadLocationList("chests");
+    }
+
+    public List<Location> getTotems() {
+        return loadLocationList("totems");
+    }
+
+    public List<Location> getExitGates() {
+        return loadLocationList("exitgates");
+    }
+
+    public Location getKillerSpawn() {
+        List<Location> spawns = loadLocationList("killer-spawn");
+        return spawns.isEmpty() ? null : spawns.get(0);
+    }
+
+    public List<Location> getSurvivorSpawns() {
+        return loadLocationList("survivor-spawns");
+    }
+
+    private List<Location> loadLocationList(String path) {
+        List<Location> locations = new ArrayList<>();
+        List<?> list = config.getList(path);
+        if (list == null) return locations;
+
+        for (Object obj : list) {
+            if (obj instanceof String) {
+                Location loc = parseLocation((String) obj);
+                if (loc != null) locations.add(loc);
+            }
+        }
+        return locations;
+    }
+
+    private Location parseLocation(String str) {
+        String[] parts = str.split(",");
+        if (parts.length < 4) return null;
+        World world = Bukkit.getWorld(parts[0].trim());
+        if (world == null) return null;
+        try {
+            double x = Double.parseDouble(parts[1].trim());
+            double y = Double.parseDouble(parts[2].trim());
+            double z = Double.parseDouble(parts[3].trim());
+            float yaw = parts.length > 4 ? Float.parseFloat(parts[4].trim()) : 0f;
+            float pitch = parts.length > 5 ? Float.parseFloat(parts[5].trim()) : 0f;
+            return new Location(world, x, y, z, yaw, pitch);
+        } catch (NumberFormatException e) {
+            return null;
+        }
+    }
+
+    public void addLocation(String path, Location loc) {
+        List<String> list = config.getStringList(path);
+        list.add(String.format("%s,%.2f,%.2f,%.2f,%.1f,%.1f",
+            loc.getWorld().getName(),
+            loc.getX(), loc.getY(), loc.getZ(),
+            loc.getYaw(), loc.getPitch()));
+        config.set(path, list);
+    }
+
+    public FileConfiguration getConfig() {
+        return config;
+    }
+}