feat: add durable relative task delays and outage recovery regression

internal/storage/mysql/task_delay_test.go

@@ -0,0 +1,34 @@
+package mysql
+
+import (
+	"encoding/json"
+	"testing"
+
+	"git.yuntuo.hk/k2safe/orbit/pulse/service"
+)
+
+func TestRelativeDelayPreservesLegacySubmissionDigest(t *testing.T) {
+	// 升级前已规范化的实际请求形状；新可选字段为零时不能改变原幂等摘要。
+	legacy := json.RawMessage(`{"queue_id":"11111111111111111111111111111111","handler":"object.prepare","handler_version":"v1","payload_version":"v1","payload":{"n":9007199254740993},"task_timeout_ms":86400000,"recovery_safety":"RECONCILE_ONLY","retry":{"max_attempts":1,"initial_delay_ms":0,"max_delay_ms":0,"attempt_timeout_ms":30000}}`)
+	var in service.SubmitInput
+	if err := json.Unmarshal(legacy, &in); err != nil {
+		t.Fatal(err)
+	}
+	in, err := service.NormalizeSubmit(in)
+	if err != nil {
+		t.Fatal(err)
+	}
+	want, err := requestDigest(legacy)
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, err := requestDigest(in)
+	if err != nil || got != want {
+		t.Fatal("zero delay changed a legacy request identity", err)
+	}
+	in.DelayMS = 1000
+	changed, err := requestDigest(in)
+	if err != nil || changed == want {
+		t.Fatal("nonzero delay missing from request identity", err)
+	}
+}