feat(ai): add tenant-safe hierarchical expense learning

server/alembic/versions/20260716_0007_hierarchical_expense_memory.py

@@ -0,0 +1,133 @@
+"""add hierarchical expense memory governance fields
+
+Revision ID: 20260716_0007
+Revises: 20260716_0006
+Create Date: 2026-07-16 12:05:00
+"""
+
+from collections.abc import Sequence
+
+import sqlalchemy as sa
+
+from alembic import op
+
+revision: str = "20260716_0007"
+down_revision: str | None = "20260716_0006"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "memory_entries",
+        sa.Column(
+            "origin_type",
+            sa.String(length=24),
+            server_default="learned",
+            nullable=False,
+        ),
+    )
+    op.add_column(
+        "memory_entries",
+        sa.Column("managed_by", sa.String(length=255), nullable=True),
+    )
+    op.add_column(
+        "memory_entries",
+        sa.Column("managed_at", sa.DateTime(timezone=True), nullable=True),
+    )
+    op.add_column(
+        "memory_entries",
+        sa.Column("management_reason", sa.String(length=255), nullable=True),
+    )
+    op.add_column(
+        "memory_entries",
+        sa.Column("policy_version", sa.String(length=64), nullable=True),
+    )
+
+    op.drop_constraint(
+        "ck_memory_entries_scope_type",
+        "memory_entries",
+        type_="check",
+    )
+    op.create_check_constraint(
+        "ck_memory_entries_scope_type",
+        "memory_entries",
+        "scope_type IN ('user', 'department', 'enterprise')",
+    )
+    op.create_check_constraint(
+        "ck_memory_entries_origin_type",
+        "memory_entries",
+        "origin_type IN ('learned', 'admin_managed')",
+    )
+    op.create_check_constraint(
+        "ck_memory_entries_scope_origin",
+        "memory_entries",
+        "(scope_type = 'user' AND origin_type = 'learned') OR "
+        "(scope_type IN ('department', 'enterprise') "
+        "AND origin_type = 'admin_managed')",
+    )
+    op.create_check_constraint(
+        "ck_memory_entries_enterprise_scope",
+        "memory_entries",
+        "scope_type != 'enterprise' OR scope_id = tenant_id",
+    )
+    op.create_check_constraint(
+        "ck_memory_entries_management_audit",
+        "memory_entries",
+        "(origin_type = 'learned' AND managed_by IS NULL "
+        "AND managed_at IS NULL AND management_reason IS NULL) OR "
+        "(origin_type = 'admin_managed' AND managed_by IS NOT NULL "
+        "AND length(trim(managed_by)) > 0 AND managed_at IS NOT NULL "
+        "AND management_reason IS NOT NULL "
+        "AND length(trim(management_reason)) > 0 "
+        "AND policy_version IS NOT NULL AND length(trim(policy_version)) > 0)",
+    )
+
+
+def downgrade() -> None:
+    op.drop_constraint(
+        "ck_memory_entries_management_audit",
+        "memory_entries",
+        type_="check",
+    )
+    op.drop_constraint(
+        "ck_memory_entries_enterprise_scope",
+        "memory_entries",
+        type_="check",
+    )
+    op.drop_constraint(
+        "ck_memory_entries_scope_origin",
+        "memory_entries",
+        type_="check",
+    )
+    op.drop_constraint(
+        "ck_memory_entries_origin_type",
+        "memory_entries",
+        type_="check",
+    )
+    op.drop_constraint(
+        "ck_memory_entries_scope_type",
+        "memory_entries",
+        type_="check",
+    )
+    # 0006 只认识个人记忆。组织记忆无法无损映射回旧结构，因此降级时
+    # 先解除组织版本间的自引用并删除组织作用域记录，个人记忆完整保留。
+    op.execute(
+        "UPDATE memory_entries SET superseded_by_id = NULL "
+        "WHERE scope_type IN ('department', 'enterprise')"
+    )
+    op.execute(
+        "DELETE FROM memory_entries "
+        "WHERE scope_type IN ('department', 'enterprise')"
+    )
+    op.create_check_constraint(
+        "ck_memory_entries_scope_type",
+        "memory_entries",
+        "scope_type = 'user'",
+    )
+
+    op.drop_column("memory_entries", "policy_version")
+    op.drop_column("memory_entries", "management_reason")
+    op.drop_column("memory_entries", "managed_at")
+    op.drop_column("memory_entries", "managed_by")
+    op.drop_column("memory_entries", "origin_type")