fix(v2): 取消失配收敛——渠道已取消(哨兵)→本地补齐+事件,不再500

CancelSubscription 本地 active/past_due 但渠道已先行取消(dashboard 手工 /
竞态未消费的 deleted webhook)时,stripe adapter 原样透传渠道拒绝,handler 映
成 500 cancel_failed——渠道取消这一事实明明已成立。新增 provider.ErrSubAlready
Canceled 哨兵,stripe adapter 识别 resource_missing / "already been canceled"
两种真实 Stripe 错误形态并 wrap;gateway.CancelSubscription 命中哨兵后走与入
站 webhook 相同的 finalizeCanceled 本地收敛,两路对同一终态天然幂等。

同 re-review 顺手核掉同型缺口:onSubscriptionActivated 的
`!created→return nil` 在入队 subscription.created 之前短路,首次入队失败后
Stripe 重投会因 created=false 永久跳过入队——通知永久丢失。改为无论 created
与否都无条件入队,outbox 唯一键 ON CONFLICT DO NOTHING 天然幂等自愈,与
finalizeCanceled/markSubscriptionPastDue/settleRenewal 同一写法。

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013nMthbVEmQquxBRKb9Fj8u

internal/provider/stripe/stripe_test.go

@@ -5,6 +5,7 @@ import (
 	"crypto/hmac"
 	"crypto/sha256"
 	"encoding/hex"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -40,6 +41,20 @@ func fakeStripeAPI(t *testing.T) *httptest.Server {
 			fmt.Fprint(w, `{"id":"cs_test_123","object":"checkout.session","amount_total":2999,"currency":"usd","payment_status":"paid"}`)
 		case r.Method == http.MethodDelete && strings.Contains(r.URL.Path, "/v1/subscriptions/sub_cancel_ok"):
 			fmt.Fprint(w, `{"id":"sub_cancel_ok","object":"subscription","status":"canceled"}`)
+		case r.Method == http.MethodDelete && strings.Contains(r.URL.Path, "/v1/subscriptions/sub_resource_missing"):
+			// 渠道已彻底删除该订阅对象:invalid_request_error + code=resource_missing(有明确
+			// 机器可读 Code)。
+			w.WriteHeader(http.StatusNotFound)
+			fmt.Fprint(w, `{"error":{"type":"invalid_request_error","code":"resource_missing","message":"No such subscription: 'sub_resource_missing'"}}`)
+		case r.Method == http.MethodDelete && strings.Contains(r.URL.Path, "/v1/subscriptions/sub_already_canceled"):
+			// 订阅对象仍在但 status=canceled,二次 Cancel:invalid_request_error,**无 code**,
+			// 只有 Stripe 实测的固定文案。
+			w.WriteHeader(http.StatusBadRequest)
+			fmt.Fprint(w, `{"error":{"type":"invalid_request_error","message":"This subscription has already been canceled."}}`)
+		case r.Method == http.MethodDelete && strings.Contains(r.URL.Path, "/v1/subscriptions/sub_cancel_other_error"):
+			// 与"已取消"无关的普通渠道拒绝(如权限/网络类),不应被误判成哨兵。
+			w.WriteHeader(http.StatusBadRequest)
+			fmt.Fprint(w, `{"error":{"type":"invalid_request_error","message":"Something else went wrong."}}`)
 		default:
 			http.Error(w, `{"error":{"message":"not found"}}`, http.StatusNotFound)
 		}
@@ -82,6 +97,53 @@ func TestCancelSubscription(t *testing.T) {
 	}
 }
 
+// TestCancelSubscriptionResourceMissingWrapsSentinel 覆盖"渠道已彻底删除该订阅对象"这一
+// 已取消形态:*stripe.Error{Type:invalid_request_error, Code:resource_missing} → wrap 成
+// provider.ErrSubAlreadyCanceled(errors.Is 可判),不是不可判别的裸字符串错误。
+func TestCancelSubscriptionResourceMissingWrapsSentinel(t *testing.T) {
+	ts := fakeStripeAPI(t)
+	defer ts.Close()
+	p := newStripe(t, ts)
+	err := p.CancelSubscription(context.Background(), "sub_resource_missing")
+	if err == nil {
+		t.Fatalf("cancel resource_missing: want error, got nil")
+	}
+	if !errors.Is(err, provider.ErrSubAlreadyCanceled) {
+		t.Fatalf("cancel resource_missing err = %v, want wraps provider.ErrSubAlreadyCanceled", err)
+	}
+}
+
+// TestCancelSubscriptionAlreadyCanceledMessageWrapsSentinel 覆盖"订阅对象仍在但 status=canceled
+// 二次 Cancel"这一形态:Stripe 对此场景**不下发机器可读 Code**,只有 invalid_request_error 类型
+// + 固定文案"already been canceled"——同样应 wrap 成哨兵。
+func TestCancelSubscriptionAlreadyCanceledMessageWrapsSentinel(t *testing.T) {
+	ts := fakeStripeAPI(t)
+	defer ts.Close()
+	p := newStripe(t, ts)
+	err := p.CancelSubscription(context.Background(), "sub_already_canceled")
+	if err == nil {
+		t.Fatalf("cancel already_canceled: want error, got nil")
+	}
+	if !errors.Is(err, provider.ErrSubAlreadyCanceled) {
+		t.Fatalf("cancel already_canceled err = %v, want wraps provider.ErrSubAlreadyCanceled", err)
+	}
+}
+
+// TestCancelSubscriptionOtherErrorNotWrapped 反例:与"已取消"无关的渠道拒绝不应被误判成
+// 哨兵,原样透传成普通错误(不能 errors.Is 命中)。
+func TestCancelSubscriptionOtherErrorNotWrapped(t *testing.T) {
+	ts := fakeStripeAPI(t)
+	defer ts.Close()
+	p := newStripe(t, ts)
+	err := p.CancelSubscription(context.Background(), "sub_cancel_other_error")
+	if err == nil {
+		t.Fatalf("cancel other error: want error, got nil")
+	}
+	if errors.Is(err, provider.ErrSubAlreadyCanceled) {
+		t.Fatalf("cancel other error err = %v, 不应误判成 ErrSubAlreadyCanceled", err)
+	}
+}
+
 func TestCapabilitiesRecurring(t *testing.T) {
 	ts := fakeStripeAPI(t)
 	defer ts.Close()