优化结构

internal/data/README.md

@@ -1 +1,28 @@
-# Data
+# Data Layer
+
+`internal/data` is the persistence composition root. It owns the shared
+database/runtime container (`Data`), database clients, configuration storage,
+and the Wire `ProviderSet`. Business repositories live in submodules so a new
+feature can be found by its domain instead of by scanning one large package.
+
+## Modules
+
+- `internal/data/system` contains the built-in administration domain: users,
+  authorities, APIs, permissions, menus, organization, dictionaries,
+  parameters, tokens, security, audit/logging, media, announcements, tasks,
+  versions, exports, bootstrap seeding, and system migrations.
+- `internal/data/payment` contains payment configuration and payment-order
+  persistence. Provider SDK implementations are separate in
+  `internal/integration/payment`.
+- `internal/data/migration` contains the version-table runner used by the
+  root migration coordinator.
+
+The root package intentionally keeps only cross-cutting infrastructure:
+database lifecycle/reloads, runtime configuration persistence, data-scope
+auditing, integration configuration storage, and migration orchestration.
+Repositories depend on narrow module seams (`system.Provider` and
+`payment.Provider`) rather than importing the root implementation details.
+
+Non-database adapters remain under `internal/integration` (storage, email,
+payment SDKs, and cache), while reusable GORM and pagination helpers live in
+`pkg/gormkit` and `pkg/pagination`.