fix(runner): 稳定异步任务重启恢复

避免恢复任务将已到期的 next_run_at 误插入 River scheduled 状态，并使用专用模型隔离重启集成测试。\n\n验证：Go 全量测试、govulncheck、pnpm lint/test/build/audit、Compose、镜像、迁移、流水线及 SemVer 门禁全部通过。

apps/api/internal/runner/queue_worker_test.go

@@ -0,0 +1,33 @@
+package runner
+
+import (
+	"testing"
+	"time"
+
+	"github.com/easyai/easyai-ai-gateway/apps/api/internal/store"
+)
+
+func TestAsyncTaskRecoveryInsertOptsMakesDueTaskImmediatelyAvailable(t *testing.T) {
+	now := time.Date(2026, time.July, 21, 3, 30, 0, 0, time.UTC)
+	opts := asyncTaskRecoveryInsertOpts(store.AsyncTaskQueueItem{
+		ID:        "due-task",
+		NextRunAt: now.Add(-time.Second),
+	}, now)
+
+	if !opts.ScheduledAt.IsZero() {
+		t.Fatalf("due recovery task should be immediately available, scheduled at %s", opts.ScheduledAt)
+	}
+}
+
+func TestAsyncTaskRecoveryInsertOptsPreservesFutureDelay(t *testing.T) {
+	now := time.Date(2026, time.July, 21, 3, 30, 0, 0, time.UTC)
+	nextRunAt := now.Add(30 * time.Second)
+	opts := asyncTaskRecoveryInsertOpts(store.AsyncTaskQueueItem{
+		ID:        "delayed-task",
+		NextRunAt: nextRunAt,
+	}, now)
+
+	if !opts.ScheduledAt.Equal(nextRunAt) {
+		t.Fatalf("future recovery task should stay delayed until %s, got %s", nextRunAt, opts.ScheduledAt)
+	}
+}