fix(billing): 重排任务复用钱包预留

平台额度跨窗口重排时保留任务已有的钱包预留，后续 Worker 领取复用同一幂等键，避免重复 reserve/release 事务。\n\n补齐排队任务取消后的原子结算释放，并允许任务 attempt 持久化软负载、满载原因和选择原因等有界路由快照。\n\n验证：go test ./...；go vet ./...；钱包预留复用与排队取消 PostgreSQL 集成测试。

apps/api/internal/store/tasks_runtime.go

@@ -901,6 +901,12 @@ SET status = 'cancelled',
     error = NULL,
     error_code = 'task_cancelled',
     error_message = NULLIF($2::text, ''),
+    billing_status = CASE
+      WHEN run_mode NOT IN ('production', 'acceptance', 'acceptance_canary') OR gateway_user_id IS NULL THEN 'not_required'
+      WHEN reservation_amount > 0 THEN 'pending'
+      ELSE 'released'
+    END,
+    billing_updated_at = now(),
     remote_task_payload = '{}'::jsonb,
     locked_by = NULL,
     locked_at = NULL,
@@ -930,7 +936,20 @@ WHERE task_id = $1::uuid
 		if _, err := tx.Exec(ctx, `DELETE FROM gateway_task_admissions WHERE task_id = $1::uuid`, taskID); err != nil {
 			return err
 		}
-		return nil
+		payloadJSON, _ := json.Marshal(map[string]any{"taskId": taskID, "reason": "queued_cancelled"})
+		_, err = tx.Exec(ctx, `
+INSERT INTO settlement_outbox (
+  task_id, event_type, action, amount, currency, pricing_snapshot, payload, status, next_attempt_at
+)
+SELECT id, 'task.billing.release', 'release', reservation_amount, billing_currency,
+       pricing_snapshot, $2::jsonb, 'pending', now()
+FROM gateway_tasks
+WHERE id = $1::uuid
+  AND run_mode IN ('production', 'acceptance', 'acceptance_canary')
+  AND gateway_user_id IS NOT NULL
+  AND reservation_amount > 0
+ON CONFLICT (task_id, event_type) DO NOTHING`, taskID, string(payloadJSON))
+		return err
 	})
 	if err != nil {
 		return GatewayTask{}, false, err
@@ -1568,6 +1587,7 @@ func minimalTaskAttemptUsage(usage map[string]any) map[string]any {
 func minimalTaskAttemptMetrics(metrics map[string]any) map[string]any {
 	return whitelistedTaskAttemptMap(metrics, []string{
 		"platformPriority", "currentPriority", "loadRatio", "loadAvoided",
+		"loadMetrics", "fullReasons", "selectionReason",
 		"cacheAffinityKey", "cacheAdjustedPriority", "cacheAffinitySamples",
 		"cacheAffinityScore", "cacheAffinityConfidence", "cacheAffinityHitRatio",
 		"cacheAffinityEMAHitRatio", "cacheAffinityLastHitRatio",