Refactor: Separated core files into subfolders

Separated core files into subfolders to improve organization and maintainability.
Created an index file for easy importing of core components.
Updated imports to reflect the new file structure.

Author: liplum

escape_wild/lib/core.dart

@@ -1,22 +1,22 @@
-import 'package:escape_wild/core.dart';
+import 'package:escape_wild/core/index.dart';
 
 /// Full name: User Action.
 ///
 /// It's to disambiguate with `Action` in flutter.
-class UAction with Moddable {
-  final UAction? parent;
+class UserAction with Moddable {
+  final UserAction? parent;
   @override
   final String name;
-  final List<UAction> subActions = [];
+  final List<UserAction> subActions = [];
 
-  UAction(this.name, {this.parent}) {
+  UserAction(this.name, {this.parent}) {
     parent?.subActions.add(this);
   }
 
   /// The sub-action should be in `parent-name.sub-name`.
-  UAction sub(String name) => UAction("${this.name}.$name", parent: this);
+  UserAction sub(String name) => UserAction("${this.name}.$name", parent: this);
 
-  factory UAction.named(String name) => UAction(name);
+  factory UserAction.named(String name) => UserAction(name);
 
   String l10nName() {
     final parent = this.parent;
@@ -28,9 +28,9 @@ class UAction with Moddable {
     }
   }
 
-  bool belongsToOrSelf(UAction ancestorOrSelf) => this == ancestorOrSelf || belongsTo(ancestorOrSelf);
+  bool belongsToOrSelf(UserAction ancestorOrSelf) => this == ancestorOrSelf || belongsTo(ancestorOrSelf);
 
-  bool belongsTo(UAction ancestor) {
+  bool belongsTo(UserAction ancestor) {
     var cur = parent;
     while (cur != null) {
       if (cur == ancestor) return true;
@@ -43,30 +43,30 @@ class UAction with Moddable {
   String toString() => name;
 
   // Move
-  static final UAction move = UAction("move"),
+  static final UserAction move = UserAction("move"),
       moveLeft = move.sub("left"),
       moveRight = move.sub("right"),
       moveUp = move.sub("up"),
       moveDown = move.sub("down"),
       moveForward = move.sub("forward"),
       moveBackward = move.sub("backward");
-  static final UAction explore = UAction("explore");
-  static final UAction gather = UAction("gather"),
+  static final UserAction explore = UserAction("explore");
+  static final UserAction gather = UserAction("gather"),
       gatherGetWater = gather.sub("get-water"),
       gatherGetWood = gather.sub("get-wood"),
       gatherGetFood = gather.sub("get-food");
 
-  static final UAction shelter = UAction("shelter"),
+  static final UserAction shelter = UserAction("shelter"),
       shelterSleepTillTomorrow = shelter.sub("sleep-till-tomorrow"),
       shelterReinforce = shelter.sub("reinforce"),
       shelterRest = shelter.sub("rest");
-  static final UAction hunt = UAction("hunt"), hunTrap = hunt.sub("trap"), hunGun = hunt.sub("gun");
-  static final UAction fish = UAction("fish");
+  static final UserAction hunt = UserAction("hunt"), hunTrap = hunt.sub("trap"), hunGun = hunt.sub("gun");
+  static final UserAction fish = UserAction("fish");
 
   // Win or lose the game.
-  static final UAction escapeWild = UAction("escape-wild"), stopHeartbeat = UAction("stop-heartbeat");
+  static final UserAction escapeWild = UserAction("escape-wild"), stopHeartbeat = UserAction("stop-heartbeat");
 
-  static final List<UAction> defaultActions = [
+  static final List<UserAction> defaultActions = [
     move,
     explore,
     shelter,
@@ -75,15 +75,15 @@ class UAction with Moddable {
   @override
   bool operator ==(Object other) {
     if (identical(this, other)) return true;
-    if (other is! UAction || other.runtimeType != runtimeType) return false;
+    if (other is! UserAction || other.runtimeType != runtimeType) return false;
     return name == other.name;
   }
 
   @override
   int get hashCode => name.hashCode;
 }
 
-extension UActionX on UAction {
+extension UActionX on UserAction {
   bool get isTopLevel => parent == null;
 
   bool get isLeaf => subActions.isEmpty;

escape_wild/lib/core/action.dart renamed to escape_wild/lib/core/action/action.dart

@@ -1,5 +1,5 @@
 import 'dart:math';
-import 'package:escape_wild/core.dart';
+import 'package:escape_wild/core/index.dart';
 
 import 'package:flutter/cupertino.dart';
 import 'package:json_annotation/json_annotation.dart';

escape_wild/lib/core/attribute/attribute.dart

@@ -1,5 +1,5 @@
 import 'package:collection/collection.dart';
-import 'package:escape_wild/core.dart';
+import 'package:escape_wild/core/index.dart';
 import 'package:jconverter/jconverter.dart';
 import 'package:json_annotation/json_annotation.dart';
 import 'package:noitcelloc/noitcelloc.dart';

escape_wild/lib/core/backpack/backpack.dart

@@ -1,7 +1,7 @@
 import 'dart:math';
 import 'package:json_annotation/json_annotation.dart';
 
-import 'package:escape_wild/core.dart';
+import 'package:escape_wild/core/index.dart';
 import 'package:flutter/widgets.dart';
 
 part 'campfire.g.dart';

escape_wild/lib/core/campfire/campfire.dart

@@ -1,4 +1,4 @@
-import 'package:escape_wild/core.dart';
+import 'package:escape_wild/core/index.dart';
 
 class Contents {
   Contents._();

escape_wild/lib/core/content.dart

@@ -1,4 +1,4 @@
-import 'package:escape_wild/core.dart';
+import 'package:escape_wild/core/index.dart';
 import 'package:jconverter/jconverter.dart';
 
 /// [ContainerCookRecipe] will transform a certain [Item] that meets [inputTags] into [result] by a certain ratio.

escape_wild/lib/core/cook/container.dart

@@ -1,6 +1,6 @@
 import 'dart:math';
 
-import 'package:escape_wild/core.dart';
+import 'package:escape_wild/core/index.dart';
 import 'package:jconverter/jconverter.dart';
 import 'package:json_annotation/json_annotation.dart';
 

escape_wild/lib/core/cook/continuous.dart

@@ -1,4 +1,4 @@
-import 'package:escape_wild/core.dart';
+import 'package:escape_wild/core/index.dart';
 import 'package:jconverter/jconverter.dart';
 import 'package:json_annotation/json_annotation.dart';
 

escape_wild/lib/core/cook/instant.dart

@@ -1,4 +1,4 @@
-import 'package:escape_wild/core.dart';
+import 'package:escape_wild/core/index.dart';
 import 'package:json_annotation/json_annotation.dart';
 
 abstract class CookRecipeProtocol with Moddable {