修复(#3): 抽奖 Stage 1 后台审计 IP/UA 丢失 + 冒烟脚本 Bearer 前缀

Closes HIF-3 (Stage 1 P1 defects from QA smoke report)

F2: admin_action_log.ip / user_agent 恒为空
- 根因：requestMeta 从 ctx 读裸字符串 key，全库无 writer 塞
- 修复：新增 AdminMetaMiddleware 用 typed constant.CtxKeyIP / CtxKeyUserAgent
- 挂载：lottery admin 组末尾（不 gate access）
- 回归护栏：UsesTypedKey + IgnoresBareStringKeys 双向断言 typed key，防止未来退化回裸字符串

F3: qa/lottery/stage1_curl.sh Bearer 前缀
- 删除两处 Bearer 前缀 + 加注释说明 ppanel AuthMiddleware 不 strip

单测 5 用例全绿；scope 严格限于 lottery admin 组，其它路径零改动；无 DB 变更。

Merged: architect review 后，将触发 staging 二次部署 — 期望这次能一并解决 shanshanzhong147 手工 SSH 后 Lottery.Enable=true 未生效的问题（若真是 mount/restart 未正确 pick up）。

pkg/constant/context.go

@@ -16,4 +16,10 @@ const (
 	CtxKeyAPIVersionUseLatest CtxKey = "apiVersionUseLatest"
 	CtxKeyAPIHeaderRaw        CtxKey = "apiHeaderRaw"
 	CtxKeyHasAppId            CtxKey = "hasAppId"
+	// CtxKeyIP / CtxKeyUserAgent are populated by AdminMetaMiddleware for
+	// audit-writing logic (admin_action_log.ip / user_agent). Both keys use
+	// the typed CtxKey so ctx.Value lookups collide-safely with any bare-string
+	// writers a future middleware might accidentally introduce.
+	CtxKeyIP        CtxKey = "ip"
+	CtxKeyUserAgent CtxKey = "user_agent"
 )