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/_sections.md

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+# Section Definitions
+
+This file defines the rule categories for Redis best practices. Rules are automatically assigned to sections based on their filename prefix.
+
+---
+
+## 1. Data Structures & Keys (data)
+**Impact:** HIGH
+**Description:** Choosing the right Redis data type and key naming conventions. Foundation for efficient Redis usage.
+
+## 2. Memory & Expiration (ram)
+**Impact:** HIGH
+**Description:** Memory limits, eviction policies, TTL strategies, and memory optimization techniques.
+
+## 3. Connection & Performance (conn)
+**Impact:** HIGH
+**Description:** Connection pooling, pipelining, timeouts, and avoiding blocking commands.
+
+## 4. JSON Documents (json)
+**Impact:** MEDIUM
+**Description:** Using Redis JSON for nested structures, partial updates, and integration with RQE.
+
+## 5. Redis Query Engine (rqe)
+**Impact:** HIGH
+**Description:** FT.CREATE, FT.SEARCH, FT.AGGREGATE, index design, field types, and query optimization.
+
+## 6. Vector Search & RedisVL (vector)
+**Impact:** HIGH
+**Description:** Vector indexes, HNSW vs FLAT, hybrid search, and RAG patterns with RedisVL.
+
+## 7. Semantic Caching (semantic-cache)
+**Impact:** MEDIUM
+**Description:** LangCache for LLM response caching, distance thresholds, and cache strategies.
+
+## 8. Streams & Pub/Sub (stream)
+**Impact:** MEDIUM
+**Description:** Choosing between Streams and Pub/Sub for messaging patterns.
+
+## 9. Clustering & Replication (cluster)
+**Impact:** MEDIUM
+**Description:** Hash tags for key colocation, read replicas, and cluster-aware patterns.
+
+## 10. Security (security)
+**Impact:** HIGH
+**Description:** Authentication, ACLs, TLS, and network security.
+
+## 11. Observability (observe)
+**Impact:** MEDIUM
+**Description:** SLOWLOG, INFO, MEMORY commands, monitoring metrics, and Redis Insight.
+