fix(workbuddy): correct CN check-in timezone and error reporting

changelog/unreleased/workbuddy-checkin-timezone-and-errors.md

@@ -0,0 +1,9 @@
+### English
+
+- WorkBuddy CN automatic check-in now reads the configured time in Asia/Shanghai instead of the container's local timezone. The supported Docker Compose install sets no `TZ`, so the time was previously treated as UTC and fired eight hours off the intended local time.
+- A dropped connection or timeout during the WorkBuddy daily check-in is now reported as a transport error instead of `checkin parse: unexpected end of JSON input`.
+
+### 中文
+
+- WorkBuddy CN 的自动签到改为按 Asia/Shanghai 解释配置的时间，不再跟随容器本地时区。官方 Docker Compose 部署未设置 `TZ`，此前该时间被当作 UTC 处理，实际触发时刻比预期偏差八小时。
+- WorkBuddy 每日签到遇到连接中断或超时时，现在会如实报告传输层错误，不再显示 `checkin parse: unexpected end of JSON input`。

internal/providers/registry.go

@@ -130,7 +130,7 @@ var WorkBuddy = ProviderDescriptor{
 			ID: "cn", Label: "CN", ChatBase: "https://copilot.tencent.com",
 			BillingBase: "https://www.codebuddy.cn", AuthBase: "https://copilot.tencent.com",
 			DefaultDomain: "codebuddy.cn",
-			Checkin:       &CheckinPolicy{Timezone: "Local"},
+			Checkin:       &CheckinPolicy{Timezone: "Asia/Shanghai"},
 		},
 		{
 			ID: "global", Label: "Global", ChatBase: "https://www.workbuddy.ai",

internal/providers/workbuddy/client.go

@@ -830,6 +830,9 @@ func (c *Client) DailyCheckin(ctx context.Context, accountID string) (string, er
 			break
 		}
 	}
+	if err != nil {
+		return "", err
+	}
 	text := strings.TrimSpace(string(body))
 	classified := Classify(status, text)
 	if classified.Kind == accounts.KindAuth {

internal/providers/workbuddy/client_test.go

@@ -1567,6 +1567,38 @@ func TestDailyCheckinAlreadyCheckedInHTTP400(t *testing.T) {
 	}
 }
 
+func TestDailyCheckinSurfacesTransportError(t *testing.T) {
+	originalDelays := dailyCheckinRetryDelays
+	dailyCheckinRetryDelays = []time.Duration{0, 0}
+	t.Cleanup(func() { dailyCheckinRetryDelays = originalDelays })
+
+	client, store := newTestClient(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		hijacker, ok := w.(http.Hijacker)
+		if !ok {
+			t.Errorf("response writer is not a hijacker")
+			return
+		}
+		conn, _, err := hijacker.Hijack()
+		if err != nil {
+			t.Errorf("hijack: %v", err)
+			return
+		}
+		_ = conn.Close()
+	}))
+	payload, _ := json.Marshal(Credential{
+		AccessToken: "at", RefreshToken: "rt", ExpiresAt: 4102444800, Domain: DomainCN, UID: "u1",
+	})
+	_ = store.SaveCredentialPayload(context.Background(), "acc1", CredentialFormat, payload)
+
+	_, err := client.DailyCheckin(context.Background(), "acc1")
+	if err == nil {
+		t.Fatal("a dropped connection must fail the check-in")
+	}
+	if strings.Contains(err.Error(), "checkin parse") {
+		t.Fatalf("transport error was reported as a parse error: %v", err)
+	}
+}
+
 func TestDailyCheckinRetriesTransientFailures(t *testing.T) {
 	var calls atomic.Int32
 	client, store := newTestClient(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {