✨ feat: WP-09 Live2D/3D——模型导入校验与非破坏命令历史

- 迁移 18：avatar_model（live2d/vrm/gltf、validated/rejected、校验报告、来源许可、当前命令指针）+ avatar_command（十类命令检查约束、(avatar,sequence) 唯一、undone 标记）
- GLB/glTF 解析器（纯 Python）：GLB magic/版本/chunk 结构校验、JSON 场景图引用一致性（scene→node→mesh→material 逐层索引越界检测）、VRM 0.x/1.0 扩展检测与 meta 提取
- 资源上限（恶意模型文件防线）：文件 200MB、节点 10 万、网格 1 万、纹理 2 千、材质 5 千、动画 1 千——超限入库 rejected 并保留报告
- Cubism model3.json 校验：Version/FileReferences 必需、moc3 引用、纹理列表、表情/动作/HitArea 计数
- 上传 MIME 白名单扩展 model/ 与 application/json
- 命令历史：十类命令（param_map/expression/physics/motion/material/texture/bone/attachment/lighting/camera）追加（sequence 单调）、撤销（标记 undone 非破坏）、rejected 模型不接受编辑（422 前置校验）
- 测试 111 项全绿（+9）：合法 GLB/VRM 检测/损坏文件/引用越界/超限/Cubism 正反例/命令历史与撤销幂等/rejected 拒编

backend/app/models.py

@@ -1333,3 +1333,72 @@ class PluginExecution(Base):
             name="status_values",
         ),
     )
+
+
+class AvatarModel(Base):
+    """Avatar 模型资产（WP-09）：live2d/vrm/gltf；校验结果与来源许可。"""
+
+    __tablename__ = "avatar_model"
+
+    id: Mapped[str] = mapped_column(
+        String, primary_key=True, default=lambda: new_id("avatar_")
+    )
+    domain_id: Mapped[str] = mapped_column(
+        ForeignKey("personal_domain.id", ondelete="cascade"), nullable=False, index=True
+    )
+    character_id: Mapped[str | None] = mapped_column(
+        ForeignKey("character.id", ondelete="set null"), nullable=True
+    )
+    name: Mapped[str] = mapped_column(String, nullable=False)
+    format: Mapped[str] = mapped_column(String, nullable=False)
+    file_id: Mapped[str] = mapped_column(
+        ForeignKey("file_asset.id", ondelete="restrict"), nullable=False
+    )
+    status: Mapped[str] = mapped_column(String, nullable=False, default="pending")
+    validation_report: Mapped[dict[str, Any]] = mapped_column(
+        JSONB, nullable=False, default=dict
+    )
+    source_info: Mapped[dict[str, Any]] = mapped_column(JSONB, nullable=False, default=dict)
+    license_terms: Mapped[str | None] = mapped_column(String, nullable=True)
+    current_command_id: Mapped[str | None] = mapped_column(
+        ForeignKey("avatar_command.id", ondelete="set null", use_alter=True), nullable=True
+    )
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now()
+    )
+
+    __table_args__ = (
+        CheckConstraint("format IN ('live2d', 'vrm', 'gltf')", name="format_values"),
+        CheckConstraint(
+            "status IN ('pending', 'validated', 'rejected')", name="status_values"
+        ),
+    )
+
+
+class AvatarCommand(Base):
+    """非破坏编辑命令历史（WP-09/ADR-006）：命令与版本可扩展到 2.0 LLM 改模。"""
+
+    __tablename__ = "avatar_command"
+
+    id: Mapped[str] = mapped_column(
+        String, primary_key=True, default=lambda: new_id("command_")
+    )
+    avatar_id: Mapped[str] = mapped_column(
+        ForeignKey("avatar_model.id", ondelete="cascade"), nullable=False, index=True
+    )
+    sequence: Mapped[int] = mapped_column(nullable=False)
+    command_type: Mapped[str] = mapped_column(String, nullable=False)
+    payload: Mapped[dict[str, Any]] = mapped_column(JSONB, nullable=False, default=dict)
+    undone: Mapped[bool] = mapped_column(nullable=False, default=False)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now()
+    )
+
+    __table_args__ = (
+        CheckConstraint(
+            "command_type IN ('param_map', 'expression', 'physics', 'motion', "
+            "'material', 'texture', 'bone', 'attachment', 'lighting', 'camera')",
+            name="command_type_values",
+        ),
+        Index("uq_avatar_command_seq", "avatar_id", "sequence", unique=True),
+    )