feat(pool): 引入 pro_first 调度预设、Pool 候选持久化跳过与诊断信息优化

- 新增 pro_first 调度预设（Pro 优先），更新 plus_first 仅针对 Plus 计划，移除 free_team_first
- Pool 内部候选（pool_key_index 不为空）跳过 DB 持久化（available/skipped/unused 均适用）
- LRU 排序新增 catalog_lru_score 回退：runtime 无记录时使用 last_used_at_unix_secs
- 执行路径 miss 诊断消息细化为中文，按 reason 分类输出可读说明
- build_local_request_candidate_status_record 补充 extra_data 和 created_at_unix_ms 字段
- OpenAI CLI 计划构建流程补充候选评估进度跟踪与 terminal reason 设置
- 前端 PoolSchedulingDialog 增加 pro_first 预设展示，修复 LRU 默认预设检测逻辑

frontend/src/views/admin/PoolManagement.vue

@@ -1328,7 +1328,10 @@ const DEFAULT_ENABLED_PRESETS = new Set(['cache_affinity', 'recent_refresh'])
 
 const DEFAULT_PRESET_LABELS: Record<string, string> = {
   lru: 'LRU',
-  free_team_first: 'Free/Team',
+  free_first: 'Free',
+  team_first: 'Team',
+  plus_first: 'Plus',
+  pro_first: 'Pro',
   recent_refresh: '刷新优先',
   quota_balanced: '额度均衡',
   single_account: '单号优先',
@@ -1400,12 +1403,15 @@ const poolSchedulingLabel = computed(() => {
     return '多维评分'
   }
 
-  const lruEnabled = cfg.lru_enabled !== false
+  const lruEnabled = cfg.scheduling_mode === 'lru' || cfg.lru_enabled === true
   const stickyTtl = Number(cfg.sticky_session_ttl_seconds ?? 3600)
   const stickyEnabled = Number.isFinite(stickyTtl) && stickyTtl > 0
 
   if (lruEnabled && stickyEnabled) return 'LRU + 粘性'
   if (lruEnabled) return 'LRU'
+  if (!cfg.scheduling_mode && (cfg.lru_enabled === null || cfg.lru_enabled === undefined)) {
+    return `${DEFAULT_ENABLED_PRESETS.size} 维度`
+  }
   if (stickyEnabled) return '粘性'
   return '随机'
 })