refactor(model): freezed 패키지 도입으로 보일러플레이트 제거

- ItemStats, CombatStats, EquipmentItem을 freezed로 마이그레이션
- copyWith, toJson/fromJson 자동 생성
- 세이브 파일 호환성 유지

pubspec.lock

@@ -1,6 +1,22 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
+  _fe_analyzer_shared:
+    dependency: transitive
+    description:
+      name: _fe_analyzer_shared
+      sha256: da0d9209ca76bde579f2da330aeb9df62b6319c834fa7baae052021b0462401f
+      url: "https://pub.dev"
+    source: hosted
+    version: "85.0.0"
+  analyzer:
+    dependency: transitive
+    description:
+      name: analyzer
+      sha256: "974859dc0ff5f37bc4313244b3218c791810d03ab3470a579580279ba971a48d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.7.1"
   archive:
     dependency: transitive
     description:
@@ -41,6 +57,70 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.1.2"
+  build:
+    dependency: transitive
+    description:
+      name: build
+      sha256: "51dc711996cbf609b90cbe5b335bbce83143875a9d58e4b5c6d3c4f684d3dda7"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.5.4"
+  build_config:
+    dependency: transitive
+    description:
+      name: build_config
+      sha256: "4ae2de3e1e67ea270081eaee972e1bd8f027d459f249e0f1186730784c2e7e33"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.2"
+  build_daemon:
+    dependency: transitive
+    description:
+      name: build_daemon
+      sha256: bf05f6e12cfea92d3c09308d7bcdab1906cd8a179b023269eed00c071004b957
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.1.1"
+  build_resolvers:
+    dependency: transitive
+    description:
+      name: build_resolvers
+      sha256: ee4257b3f20c0c90e72ed2b57ad637f694ccba48839a821e87db762548c22a62
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.5.4"
+  build_runner:
+    dependency: "direct dev"
+    description:
+      name: build_runner
+      sha256: "382a4d649addbfb7ba71a3631df0ec6a45d5ab9b098638144faf27f02778eb53"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.5.4"
+  build_runner_core:
+    dependency: transitive
+    description:
+      name: build_runner_core
+      sha256: "85fbbb1036d576d966332a3f5ce83f2ce66a40bea1a94ad2d5fc29a19a0d3792"
+      url: "https://pub.dev"
+    source: hosted
+    version: "9.1.2"
+  built_collection:
+    dependency: transitive
+    description:
+      name: built_collection
+      sha256: "376e3dd27b51ea877c28d525560790aee2e6fbb5f20e2f85d5081027d94e2100"
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.1.1"
+  built_value:
+    dependency: transitive
+    description:
+      name: built_value
+      sha256: "7931c90b84bc573fef103548e354258ae4c9d28d140e41961df6843c5d60d4d8"
+      url: "https://pub.dev"
+    source: hosted
+    version: "8.12.3"
   characters:
     dependency: transitive
     description:
@@ -73,6 +153,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.1.2"
+  code_builder:
+    dependency: transitive
+    description:
+      name: code_builder
+      sha256: "6a6cab2ba4680d6423f34a9b972a4c9a94ebe1b62ecec4e1a1f2cba91fd1319d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.11.1"
   collection:
     dependency: transitive
     description:
@@ -81,6 +169,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.19.1"
+  convert:
+    dependency: transitive
+    description:
+      name: convert
+      sha256: b30acd5944035672bc15c6b7a8b47d773e41e2f17de064350988c5d02adb1c68
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.2"
   crypto:
     dependency: transitive
     description:
@@ -97,6 +193,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.0.8"
+  dart_style:
+    dependency: transitive
+    description:
+      name: dart_style
+      sha256: "8a0e5fba27e8ee025d2ffb4ee820b4e6e2cf5e4246a6b1a477eb66866947e0bb"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.1"
   fake_async:
     dependency: "direct dev"
     description:
@@ -165,6 +269,70 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  freezed:
+    dependency: "direct dev"
+    description:
+      name: freezed
+      sha256: "59a584c24b3acdc5250bb856d0d3e9c0b798ed14a4af1ddb7dc1c7b41df91c9c"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.5.8"
+  freezed_annotation:
+    dependency: "direct main"
+    description:
+      name: freezed_annotation
+      sha256: c2e2d632dd9b8a2b7751117abcfc2b4888ecfe181bd9fca7170d9ef02e595fe2
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.4.4"
+  frontend_server_client:
+    dependency: transitive
+    description:
+      name: frontend_server_client
+      sha256: f64a0333a82f30b0cca061bc3d143813a486dc086b574bfb233b7c1372427694
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.0.0"
+  glob:
+    dependency: transitive
+    description:
+      name: glob
+      sha256: c3f1ee72c96f8f78935e18aa8cecced9ab132419e8625dc187e1c2408efc20de
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.3"
+  graphs:
+    dependency: transitive
+    description:
+      name: graphs
+      sha256: "741bbf84165310a68ff28fe9e727332eef1407342fca52759cb21ad8177bb8d0"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.3.2"
+  http:
+    dependency: transitive
+    description:
+      name: http
+      sha256: "87721a4a50b19c7f1d49001e51409bddc46303966ce89a65af4f4e6004896412"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.6.0"
+  http_multi_server:
+    dependency: transitive
+    description:
+      name: http_multi_server
+      sha256: aa6199f908078bb1c5efb8d8638d4ae191aac11b311132c3ef48ce352fb52ef8
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.2"
+  http_parser:
+    dependency: transitive
+    description:
+      name: http_parser
+      sha256: "178d74305e7866013777bab2c3d8726205dc5a4dd935297175b19a23a2e66571"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.1.2"
   image:
     dependency: transitive
     description:
@@ -181,14 +349,38 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.20.2"
-  json_annotation:
+  io:
     dependency: transitive
+    description:
+      name: io
+      sha256: dfd5a80599cf0165756e3181807ed3e77daf6dd4137caaad72d0b7931597650b
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.5"
+  js:
+    dependency: transitive
+    description:
+      name: js
+      sha256: "53385261521cc4a0c4658fd0ad07a7d14591cf8fc33abbceae306ddb974888dc"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.7.2"
+  json_annotation:
+    dependency: "direct main"
     description:
       name: json_annotation
       sha256: "1ce844379ca14835a50d2f019a3099f419082cfdd231cd86a142af94dd5c6bb1"
       url: "https://pub.dev"
     source: hosted
     version: "4.9.0"
+  json_serializable:
+    dependency: "direct dev"
+    description:
+      name: json_serializable
+      sha256: c50ef5fc083d5b5e12eef489503ba3bf5ccc899e487d691584699b4bdefeea8c
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.9.5"
   just_audio:
     dependency: "direct main"
     description:
@@ -245,6 +437,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "5.1.1"
+  logging:
+    dependency: transitive
+    description:
+      name: logging
+      sha256: c8245ada5f1717ed44271ed1c26b8ce85ca3228fd2ffdb75468ab01979309d61
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.3.0"
   matcher:
     dependency: transitive
     description:
@@ -269,6 +469,22 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.16.0"
+  mime:
+    dependency: transitive
+    description:
+      name: mime
+      sha256: "41a20518f0cb1256669420fdba0cd90d21561e560ac240f26ef8322e45bb7ed6"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.0"
+  package_config:
+    dependency: transitive
+    description:
+      name: package_config
+      sha256: f096c55ebb7deb7e384101542bfba8c52696c1b56fca2eb62827989ef2353bbc
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.0"
   path:
     dependency: transitive
     description:
@@ -349,6 +565,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.1.8"
+  pool:
+    dependency: transitive
+    description:
+      name: pool
+      sha256: "978783255c543aa3586a1b3c21f6e9d720eb315376a915872c61ef8b5c20177d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.5.2"
   posix:
     dependency: transitive
     description:
@@ -357,6 +581,22 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "6.0.3"
+  pub_semver:
+    dependency: transitive
+    description:
+      name: pub_semver
+      sha256: "5bfcf68ca79ef689f8990d1160781b4bad40a3bd5e5218ad4076ddb7f4081585"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.0"
+  pubspec_parse:
+    dependency: transitive
+    description:
+      name: pubspec_parse
+      sha256: "0560ba233314abbed0a48a2956f7f022cce7c3e1e73df540277da7544cad4082"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.5.0"
   rxdart:
     dependency: transitive
     description:
@@ -421,11 +661,43 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.4.1"
+  shelf:
+    dependency: transitive
+    description:
+      name: shelf
+      sha256: e7dd780a7ffb623c57850b33f43309312fc863fb6aa3d276a754bb299839ef12
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.4.2"
+  shelf_web_socket:
+    dependency: transitive
+    description:
+      name: shelf_web_socket
+      sha256: "3632775c8e90d6c9712f883e633716432a27758216dfb61bd86a8321c0580925"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.0"
   sky_engine:
     dependency: transitive
     description: flutter
     source: sdk
     version: "0.0.0"
+  source_gen:
+    dependency: transitive
+    description:
+      name: source_gen
+      sha256: "35c8150ece9e8c8d263337a265153c3329667640850b9304861faea59fc98f6b"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.0"
+  source_helper:
+    dependency: transitive
+    description:
+      name: source_helper
+      sha256: a447acb083d3a5ef17f983dd36201aeea33fedadb3228fa831f2f0c92f0f3aca
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.3.7"
   source_span:
     dependency: transitive
     description:
@@ -450,6 +722,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.1.4"
+  stream_transform:
+    dependency: transitive
+    description:
+      name: stream_transform
+      sha256: ad47125e588cfd37a9a7f86c7d6356dde8dfe89d071d293f80ca9e9273a33871
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.1"
   string_scanner:
     dependency: transitive
     description:
@@ -482,6 +762,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.7.6"
+  timing:
+    dependency: transitive
+    description:
+      name: timing
+      sha256: "62ee18aca144e4a9f29d212f5a4c6a053be252b895ab14b5821996cff4ed90fe"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.2"
   typed_data:
     dependency: transitive
     description:
@@ -514,6 +802,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "15.0.2"
+  watcher:
+    dependency: transitive
+    description:
+      name: watcher
+      sha256: "1398c9f081a753f9226febe8900fce8f7d0a67163334e1c94a2438339d79d635"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.2.1"
   web:
     dependency: transitive
     description:
@@ -522,6 +818,22 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.1.1"
+  web_socket:
+    dependency: transitive
+    description:
+      name: web_socket
+      sha256: "34d64019aa8e36bf9842ac014bb5d2f5586ca73df5e4d9bf5c936975cae6982c"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.1"
+  web_socket_channel:
+    dependency: transitive
+    description:
+      name: web_socket_channel
+      sha256: d645757fb0f4773d602444000a8131ff5d48c9e47adfe9772652dd1a4f2d45c8
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.3"
   xdg_directories:
     dependency: transitive
     description: