feat(T+): 完成数据贯通与自动接入闭环

打通 T+ 快照、业务、发货、回款和核算准备链路，保留来源差异并提供待补状态。
新增业务自动接入任务、跨平台读取服务托管、权限复核、来源关联和前端核对页面。
补充迁移、隔离集成测试、浏览器模拟验收及角色授权边界修复。

backend/app/models/tplus_workbench.py

@@ -21,6 +21,9 @@ class TPlusSourceHead(Base):
             name="uk_tplus_source_heads_source_entity_id",
         ),
         Index("idx_tplus_source_heads_batch_entity", "batch_no", "entity_type"),
+        Index("idx_tplus_source_heads_parent", "source_database", "entity_type", "source_parent_id"),
+        Index("idx_tplus_source_heads_customer_date", "source_database", "entity_type", "source_customer_id", "source_date"),
+        Index("idx_tplus_source_heads_date", "source_database", "entity_type", "source_date", "id"),
     )
     id: Mapped[int] = mapped_column(
         BIGINT_UNSIGNED, primary_key=True, autoincrement=True, comment="主键ID"
@@ -29,6 +32,9 @@ class TPlusSourceHead(Base):
     entity_type: Mapped[str] = mapped_column(String(32), comment="实体类型")
     source_id: Mapped[str] = mapped_column(String(64), comment="源内部ID")
     record_id: Mapped[int] = mapped_column(BIGINT_UNSIGNED, comment="原始快照ID")
+    source_parent_id: Mapped[str | None] = mapped_column(String(64), comment="源父单据ID查询投影")
+    source_customer_id: Mapped[str | None] = mapped_column(String(64), comment="源客户ID查询投影")
+    source_date: Mapped[str | None] = mapped_column(String(10), comment="源业务日期查询投影")
     batch_no: Mapped[str] = mapped_column(String(32), comment="最后观察批次")