Remove internal phase comments and format code

Strip all Phase references, TODO/FUTURE roadmap notes, and internal
planning comments from the codebase. Run Prettier for consistent
formatting across all Java files.

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

@@ -14,7 +14,7 @@ import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.item.ItemStack;
 
 /**
- * Key management commands for Phase 18.
+ * Key management commands.
  *
  * Commands:
  *   /key claim - Claim the key you're holding