feat(rbac): add roles and permissions

backend/hermes/app/models/rbac.py

@@ -0,0 +1,58 @@
+from datetime import datetime
+
+from sqlalchemy import Boolean, DateTime, ForeignKey, String, Table, Column, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.db.database import Base
+
+
+role_permissions = Table(
+    "role_permissions",
+    Base.metadata,
+    Column("role_id", ForeignKey("roles.id", ondelete="CASCADE"), primary_key=True),
+    Column("permission_id", ForeignKey("permissions.id", ondelete="CASCADE"), primary_key=True),
+)
+
+
+class Role(Base):
+    __tablename__ = "roles"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    name: Mapped[str] = mapped_column(String(80), unique=True, index=True)
+    display_name: Mapped[str] = mapped_column(String(120))
+    description: Mapped[str] = mapped_column(String(500), default="", server_default="")
+    is_system: Mapped[bool] = mapped_column(Boolean, default=False, server_default="false")
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+        onupdate=func.now(),
+    )
+
+    permissions: Mapped[list["Permission"]] = relationship(
+        secondary=role_permissions,
+        back_populates="roles",
+        lazy="selectin",
+    )
+
+
+class Permission(Base):
+    __tablename__ = "permissions"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    name: Mapped[str] = mapped_column(String(120), unique=True, index=True)
+    display_name: Mapped[str] = mapped_column(String(160))
+    description: Mapped[str] = mapped_column(String(500), default="", server_default="")
+    module: Mapped[str] = mapped_column(String(80), index=True)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+        onupdate=func.now(),
+    )
+
+    roles: Mapped[list[Role]] = relationship(
+        secondary=role_permissions,
+        back_populates="permissions",
+        lazy="selectin",
+    )