refactor(api): TOML 配置 SSOT、统一错误契约、Auth/事务加固与可观测性 (#33)

配置 SSOT（TOML + .env）
统一错误契约
Auth 与事务边界
Redis / Celery 可靠性:业务 Redis（DB/0）与 Celery broker/backend（DB/1）显式拆分；连接池、sync client
可观测性（OpenTelemetry + LGTM）

api/.agents/skills/redis-development/rules/rqe-query-optimization.md

@@ -0,0 +1,49 @@
+---
+title: Write Efficient Queries
+impact: HIGH
+impactDescription: Proper filtering reduces query time by orders of magnitude
+tags: rqe, ft.search, query, performance, filters
+description: Write Efficient Queries
+alwaysApply: true
+---
+
+## Write Efficient Queries
+
+Be specific and use filters to reduce the result set early.
+
+**Correct:** Use specific filters and limit results.
+
+```
+# Good: Specific query with filters
+FT.SEARCH idx:products "@category:{electronics} @price:[100 500]"
+    LIMIT 0 20
+    RETURN 3 name price category
+
+# Good: Use SORTBY and LIMIT
+FT.SEARCH idx:products "@name:laptop"
+    SORTBY price ASC
+    LIMIT 0 10
+```
+
+**Incorrect:** Broad queries returning large result sets.
+
+```
+# Bad: Wildcard prefix scans entire index
+FT.SEARCH idx:products "*" LIMIT 0 10000
+
+# Bad: Loading all fields from source document
+FT.AGGREGATE idx:products "*" LOAD *
+```
+
+**Performance tips:**
+- Add `SORTABLE` to fields used in `SORTBY`
+- Use `TAG SORTABLE UNF` for best performance on tag fields
+- Use `NOSTEM` if you don't need stemming
+- Profile queries with `FT.PROFILE`
+
+```
+FT.PROFILE idx:products SEARCH QUERY "@category:{electronics}"
+```
+
+Reference: [Redis Search Query Syntax](https://redis.io/docs/latest/develop/interact/search-and-query/query/)
+