refactor(structure): group platform, infra, and shared packages

Reorganize internal packages into platform/infra/shared layers and update
imports, docs, and seed-count tests to match current system configs.

internal/infra/task/permanent_error.go

@@ -0,0 +1,35 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package task
+
+import (
+	"strings"
+
+	"github.com/hibiken/asynq"
+)
+
+const defaultPermanentErrorMessage = "任务无法继续执行"
+
+type permanentTaskError struct {
+	message string
+}
+
+// PermanentError marks a safe domain message as a non-retryable task failure.
+// It intentionally accepts no underlying error so Error never exposes provider,
+// URL, header, response-body, or other sensitive implementation details.
+func PermanentError(message string) error {
+	message = strings.TrimSpace(message)
+	if message == "" {
+		message = defaultPermanentErrorMessage
+	}
+	return &permanentTaskError{message: message}
+}
+
+func (e *permanentTaskError) Error() string {
+	return e.message
+}
+
+func (e *permanentTaskError) Unwrap() error {
+	return asynq.SkipRetry
+}