初始提交：项目基础结构

- backend: FastAPI 后端服务 (Python)
- frontend: React + Tauri 前端应用
- docker-compose.yml: 容器编排配置

backend/app/models/task_log.py

@@ -0,0 +1,44 @@
+"""任务操作日志模型"""
+import uuid
+from datetime import datetime, timezone
+from sqlalchemy import String, DateTime, ForeignKey, Text
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.models.base import Base
+
+
+class TaskLog(Base):
+    __tablename__ = "task_logs"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), primary_key=True, default=uuid.uuid4,
+    )
+
+    # ---- 物理外键（关联本库 tasks） ----
+    task_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("tasks.id"), nullable=False, index=True, comment="所属任务ID",
+    )
+
+    # ---- 逻辑外键（关联老系统用户表，仅存储 ID，无物理约束） ----
+    operator_id: Mapped[str | None] = mapped_column(
+        String(64), nullable=True, comment="操作人ID(逻辑外键→老系统)",
+    )
+
+    action_type: Mapped[str] = mapped_column(
+        String(50), nullable=False, comment="操作类型",
+    )
+
+    remark: Mapped[str | None] = mapped_column(
+        Text, nullable=True, comment="备注",
+    )
+
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), comment="创建时间",
+    )
+
+    # ---- 关系 ----
+    task: Mapped["Task"] = relationship("Task", lazy="selectin")
+
+    def __repr__(self) -> str:
+        return f"<TaskLog {self.action_type} @ {self.created_at}>"