refactor(render): 抽象图形后端并迁移渲染器 (#313)

* refactor(render): 抽象图形后端并迁移渲染器

- 新增 engine-shared 包，定义 GraphicsBackend trait 抽象层
- 实现 WebGL2Backend 作为首个后端实现
- 迁移 Renderer2D、SpriteBatch、GridRenderer、GizmoRenderer 使用新抽象
- 修复 VAO 创建时索引缓冲区绑定状态泄漏问题
- 新增 create_vertex_buffer_sized 方法支持预分配缓冲区

* fix(serialization): 修复序列化循环引用导致栈溢出

- 在 serializeValue 添加 WeakSet 检测循环引用
- 跳过已访问对象避免无限递归

* refactor(serialization): 提取 ValueSerializer 统一序列化逻辑

- 新增 ValueSerializer 模块，函数式设计
- 支持可扩展类型处理器注册
- 移除 ComponentSerializer/SceneSerializer 重复代码
- 内置 Date/Map/Set 类型支持

* fix: CodeQL 类型检查警告

packages/engine-shared/Cargo.toml

@@ -0,0 +1,33 @@
+[package]
+name = "es-engine-shared"
+version = "0.1.0"
+edition = "2021"
+authors = ["ESEngine Team"]
+description = "Shared types and traits for ESEngine graphics backends | ESEngine 图形后端共享类型和 trait"
+license = "MIT"
+repository = "https://github.com/esengine/esengine"
+keywords = ["game-engine", "graphics", "abstraction"]
+categories = ["game-engines", "graphics"]
+
+[lib]
+crate-type = ["rlib"]
+
+[features]
+default = []
+# 启用 serde 序列化支持 | Enable serde serialization support
+serde = ["dep:serde"]
+
+[dependencies]
+# 数学库 | Math library
+glam = { version = "0.24", features = ["bytemuck"] }
+
+# 错误处理 | Error handling
+thiserror = "1.0"
+
+# 可选：序列化 | Optional: serialization
+serde = { version = "1.0", features = ["derive"], optional = true }
+
+# 字节操作 | Byte manipulation
+bytemuck = { version = "1.14", features = ["derive"] }
+
+[dev-dependencies]