fix(build): 修复网关构建失败并收口候选选择与 finalize 回归

- 补齐 DecisionTraceCandidate 新增字段，修复审计测试构造
- 修正 usage 内存仓库的 created_at_unix_ms 字段引用与秒/毫秒换算
- 将 build_minimal_candidate_selection 重构为输入对象，消除 clippy 参数过多问题
- 修复 admin global model created_at 旧字段残留引用
- 修复 openai:cli 与 openai:compact 同家族 finalize 在 needs_conversion=true 时的成功回落逻辑
- 清理 aether-gateway 中的 derive/default 与 needless borrow 等 clippy 问题

crates/aether-scheduler-core/src/lib.rs

@@ -19,8 +19,9 @@ pub use candidate::{
     candidate_is_selectable_with_runtime_state, candidate_supports_required_capability,
     collect_global_model_names_for_required_capability, collect_selectable_candidates_from_keys,
     compare_candidates_by_priority_mode, reorder_candidates_by_scheduler_health,
-    requested_capability_priority_for_candidate, CandidateRuntimeSelectabilityInput,
-    SchedulerMinimalCandidateSelectionCandidate, SchedulerPriorityMode,
+    requested_capability_priority_for_candidate, BuildMinimalCandidateSelectionInput,
+    CandidateRuntimeSelectabilityInput, SchedulerMinimalCandidateSelectionCandidate,
+    SchedulerPriorityMode,
 };
 pub use health::{
     aggregate_provider_key_health_score, count_recent_active_requests_for_api_key,