refactor(schema): 重构数据库模型和 schema，清理废弃表

backend/src/models/__init__.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 from .agent_chat_message import AgentChatMessage
 from .agent_chat_session import AgentChatSession
 from .auth_user import AuthUser
+from .invite_code import InviteCode
 from .llm import Llm
 from .llm_factory import LlmFactory
 from .points_ledger import PointsLedger
@@ -14,6 +15,7 @@ __all__ = [
     "AgentChatMessage",
     "AgentChatSession",
     "AuthUser",
+    "InviteCode",
     "Llm",
     "LlmFactory",
     "PointsLedger",

backend/src/models/llm.py

@@ -21,6 +21,4 @@ class Llm(TimestampMixin, SoftDeleteMixin, Base):
         nullable=False,
         index=True,
     )
-    model_code: Mapped[str] = mapped_column(
-        String(50), nullable=False, unique=True, index=True
-    )
+    model_code: Mapped[str] = mapped_column(String(50), nullable=False, unique=True)

backend/src/models/llm_factory.py

@@ -15,8 +15,6 @@ class LlmFactory(TimestampMixin, SoftDeleteMixin, Base):
     id: Mapped[uuid.UUID] = mapped_column(
         UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
     )
-    name: Mapped[str] = mapped_column(
-        String(50), nullable=False, unique=True, index=True
-    )
+    name: Mapped[str] = mapped_column(String(50), nullable=False, unique=True)
     request_url: Mapped[str] = mapped_column(String(255), nullable=False)
     avatar: Mapped[str | None] = mapped_column(Text, nullable=True)

backend/src/models/profile.py

@@ -34,3 +34,8 @@ class Profile(TimestampMixin, SoftDeleteMixin, Base):
         server_default=text("'{}'::jsonb"),
         default=dict,
     )
+    referred_by: Mapped[uuid.UUID | None] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("profiles.id", ondelete="SET NULL"),
+        nullable=True,
+    )