fix(ai): 审计问题修复 — 错误映射/性能/SSE/依赖规范化

- C3: handler 中 .map_err(AppError::Internal) 改为 ? 操作符，
  利用 From<AiError> for AppError 实现正确的 HTTP 状态码映射
- H1: AiState 预构建在 AppState 初始化时，避免每次请求重建
  ClaudeProvider/AnalysisService/PromptService/UsageService
- H3: stream_analyze 的 user_id 参数传递到 created_by/updated_by
- H5: SSE 事件添加 .event("chunk"/"error"/"done") 类型字段
- L3: erp-ai Cargo.toml 依赖改用 workspace 引用
  (reqwest/handlebars/sha2/hex)
- 修复 erp-health 编译错误: points_handler 缺少 ColumnTrait 导入,
  points_service 版本字段部分移动问题

crates/erp-ai/Cargo.toml

@@ -19,7 +19,7 @@ tracing.workspace = true
 thiserror.workspace = true
 utoipa.workspace = true
 async-trait.workspace = true
-reqwest = { version = "0.12", features = ["stream", "json"] }
-handlebars = "6"
-sha2 = "0.10"
-hex = "0.4"
+reqwest.workspace = true
+handlebars.workspace = true
+sha2.workspace = true
+hex.workspace = true