Initial commit: KPI Management System Backend

Features:
- FastAPI backend with JWT authentication
- MySQL database with SQLAlchemy ORM
- KPI workflow: draft → pending → approved → evaluation → completed
- Ollama LLM API integration for AI features
- Gitea API integration for version control
- Complete API endpoints for KPI, dashboard, notifications

Tables: KPI_D_* prefix naming convention

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/models/department.py

@@ -0,0 +1,42 @@
+"""
+部門 Model
+"""
+from datetime import datetime
+from typing import Optional, List, TYPE_CHECKING
+
+from sqlalchemy import String, Integer, Boolean, DateTime, ForeignKey
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.core.database import Base
+
+if TYPE_CHECKING:
+    from app.models.employee import Employee
+
+
+class Department(Base):
+    """部門"""
+
+    __tablename__ = "KPI_D_departments"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    code: Mapped[str] = mapped_column(String(20), unique=True, nullable=False)
+    name: Mapped[str] = mapped_column(String(100), nullable=False)
+    level: Mapped[str] = mapped_column(String(20), default="DEPT")  # COMPANY, BU, DEPT, TEAM
+    parent_id: Mapped[Optional[int]] = mapped_column(ForeignKey("KPI_D_departments.id"))
+    is_active: Mapped[bool] = mapped_column(Boolean, default=True)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow)
+    updated_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
+
+    # Relationships
+    parent: Mapped[Optional["Department"]] = relationship(
+        "Department", remote_side=[id], back_populates="children"
+    )
+    children: Mapped[List["Department"]] = relationship(
+        "Department", back_populates="parent"
+    )
+    employees: Mapped[List["Employee"]] = relationship(
+        "Employee", back_populates="department"
+    )
+
+    def __repr__(self) -> str:
+        return f"<Department {self.code}: {self.name}>"