feat(llm): update

backend/llm.txt

@@ -14,6 +14,7 @@ This file condenses `backend/docs/dev/http_api.md` + `backend/docs/dev/model.md`
 - DO keep controller methods thin: parse/bind → call `services.*` → return result/error.
 - DO regenerate code after changes (routes/docs/models).
 - MUST: in `backend/app/services`, prefer the generated GORM-Gen DAO (`backend/database/models/*`) for DB access; treat raw `*gorm.DB` usage as a last resort.
+- MUST: When building queries in services, improve readability by using the assignment: `tbl, query := models.<Table>Query.QueryContext(ctx)`. Then use `tbl` for field references (e.g., `tbl.ID.Eq(...)`) and `query` for chaining methods.
 - MUST: service-layer transactions MUST use `models.Q.Transaction(func(tx *models.Query) error { ... })`; DO NOT use raw `*_db.Transaction(...)` / `db.Transaction(...)` in services unless Gen cannot express the required operation.
 - MUST: after adding/removing/renaming any files under `backend/app/services/`, run `atomctl gen service --path ./app/services` to regenerate `backend/app/services/services.gen.go`; DO NOT edit `services.gen.go` manually.
 - DO add `// @provider` above every controller/service `struct` declaration.
@@ -208,7 +209,7 @@ In this case:
 ### Job（一次性任务）
 
 - `Kind() string`：任务类型标识（job kind）；改名会导致“新旧任务类型不一致”。
-- `InsertOpts() river.InsertOpts` : 默认入队参数（队列、优先级、最大重试、唯一任务策略等）。
+- `InsertOpts() river.InsertOpts`：默认入队参数（队列、优先级、最大重试、唯一任务策略等）。
 - `UniqueID() string`（项目约定）：周期任务 handle 的稳定 key；通常 `return Kind()`。
 
 ### Worker（执行器）