Clean repo for open source release

Remove build artifacts, dev tool configs, unused dependencies,
and third-party source dumps. Add proper README, update .gitignore,
clean up Makefile.

src/main/java/com/tiedup/remake/commands/CommandHelper.java

@@ -0,0 +1,91 @@
+package com.tiedup.remake.commands;
+
+import com.tiedup.remake.network.ModNetwork;
+import com.tiedup.remake.network.sync.PacketSyncBindState;
+import com.tiedup.remake.state.PlayerBindState;
+import java.util.Optional;
+import java.util.function.Predicate;
+import net.minecraft.commands.CommandSourceStack;
+import net.minecraft.network.chat.Component;
+import net.minecraft.server.level.ServerPlayer;
+
+/**
+ * Utility methods for command handling.
+ */
+public final class CommandHelper {
+
+    /**
+     * Permission level 2 (OP) requirement for commands.
+     * Use with: .requires(CommandHelper.REQUIRES_OP)
+     */
+    public static final Predicate<CommandSourceStack> REQUIRES_OP = source ->
+        source.hasPermission(2);
+
+    private CommandHelper() {}
+
+    /**
+     * Get the player from command source, or send failure message and return empty.
+     *
+     * Usage:
+     * <pre>
+     * var playerOpt = CommandHelper.getPlayerOrFail(source);
+     * if (playerOpt.isEmpty()) return 0;
+     * ServerPlayer player = playerOpt.get();
+     * </pre>
+     *
+     * @param source The command source
+     * @return Optional containing the player, or empty if source is not a player
+     */
+    public static Optional<ServerPlayer> getPlayerOrFail(
+        CommandSourceStack source
+    ) {
+        if (source.getEntity() instanceof ServerPlayer player) {
+            return Optional.of(player);
+        }
+        source.sendFailure(Component.literal("Must be a player"));
+        return Optional.empty();
+    }
+
+    /**
+     * Get the player from command source without sending failure message.
+     *
+     * @param source The command source
+     * @return Optional containing the player, or empty if source is not a player
+     */
+    public static Optional<ServerPlayer> getPlayer(CommandSourceStack source) {
+        if (source.getEntity() instanceof ServerPlayer player) {
+            return Optional.of(player);
+        }
+        return Optional.empty();
+    }
+
+    /**
+     * Check if source is a player.
+     *
+     * @param source The command source
+     * @return true if source is a player
+     */
+    public static boolean isPlayer(CommandSourceStack source) {
+        return source.getEntity() instanceof ServerPlayer;
+    }
+
+    /**
+     * Sync player state to client after command changes.
+     *
+     * @param player The player to sync
+     * @param state The player's bind state
+     */
+    public static void syncPlayerState(
+        ServerPlayer player,
+        PlayerBindState state
+    ) {
+        // Sync V2 equipment
+        com.tiedup.remake.v2.bondage.capability.V2EquipmentHelper.sync(player);
+
+        // Sync bind state
+        PacketSyncBindState statePacket = PacketSyncBindState.fromPlayer(player);
+        if (statePacket != null) {
+            ModNetwork.sendToPlayer(statePacket, player);
+        }
+    }
+}