feat: generate approved profile snapshots

app/model/memory.py

@@ -75,6 +75,25 @@ class MemorySyncOutbox(Base):
     processed_at: Mapped[datetime | None] = mapped_column(DateTime)
 
 
+class ProfileSnapshot(Base):
+    """客户画像版本快照；只有审核通过的候选才能生成当前版本。"""
+
+    __tablename__ = "profile_snapshots"
+
+    id: Mapped[int] = mapped_column(BigInteger, primary_key=True)
+    profile_uuid: Mapped[str | None] = mapped_column(String(36), unique=True)
+    customer_id: Mapped[int] = mapped_column(BigInteger, nullable=False)
+    version: Mapped[int] = mapped_column(BigInteger, nullable=False)
+    snapshot: Mapped[dict[str, Any]] = mapped_column(JSON, nullable=False)
+    generation_basis: Mapped[dict[str, Any] | None] = mapped_column(JSON)
+    snapshot_hash: Mapped[str | None] = mapped_column(String(64))
+    is_current: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+    current_customer_id: Mapped[int | None] = mapped_column(BigInteger, unique=True)
+    generated_at: Mapped[datetime | None] = mapped_column(DateTime)
+    created_at: Mapped[datetime] = mapped_column(DateTime, nullable=False)
+    updated_at: Mapped[datetime] = mapped_column(DateTime, nullable=False)
+
+
 class MemoryConflict(Base):
     """记忆冲突；库列名为 `status`，`resolution`/`severity`/`resolved_by` 必须映射。"""