feat(aws-compat): queue attributes for Terraform (FifoQueue, ContentBasedDeduplication, Policy, real timestamps)

- GetQueueAttributes now returns FifoQueue, ContentBasedDeduplication, Policy and
  real Created/LastModifiedTimestamp (previously missing/stubbed '0000000000')
- Queue: add CreatedAt, LastModifiedAt, Policy, ContentBasedDeduplication
- parse FifoQueue/ContentBasedDeduplication in both protocols (StringToBool)
- Policy/RedriveAllowPolicy: normalize JSON-string form to object (JSON protocol
  sent them as string -> SetQueueAttributes failed with InvalidParameterValue)
- persistence: keep new fields in meta DTO + backfill empty timestamps on load
- FIFO dedup is inherent: IsDuplicate/InitDuplicatation gate on IsFIFO only
  (env flag EnableDuplicates=false disabled dedup for all FIFO queues)

app/gosqs/get_queue_attributes.go

@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"strconv"
 	"strings"
+	"time"
 
 	"shared-sqs/app/interfaces"
 	"shared-sqs/app/models"
@@ -86,6 +87,13 @@ func GetQueueAttributesV1(req *http.Request) (int, interfaces.AbstractResponseBo
 	if shouldInclude("VisibilityTimeout") {
 		queueAttributes = append(queueAttributes, models.Attribute{Name: "VisibilityTimeout", Value: strconv.Itoa(queue.VisibilityTimeout)})
 	}
+	// FIFO-атрибуты: читаются Terraform (aws_sqs_queue) и aws cli; без них — drift.
+	if shouldInclude("FifoQueue") {
+		queueAttributes = append(queueAttributes, models.Attribute{Name: "FifoQueue", Value: strconv.FormatBool(queue.IsFIFO)})
+	}
+	if shouldInclude("ContentBasedDeduplication") {
+		queueAttributes = append(queueAttributes, models.Attribute{Name: "ContentBasedDeduplication", Value: strconv.FormatBool(queue.ContentBasedDeduplication)})
+	}
 	if shouldInclude("ApproximateNumberOfMessages") {
 		queueAttributes = append(queueAttributes, models.Attribute{Name: "ApproximateNumberOfMessages", Value: strconv.Itoa(queue.LiveCount())})
 	}
@@ -93,10 +101,10 @@ func GetQueueAttributesV1(req *http.Request) (int, interfaces.AbstractResponseBo
 		queueAttributes = append(queueAttributes, models.Attribute{Name: "ApproximateNumberOfMessagesNotVisible", Value: strconv.Itoa(numberOfHiddenMessagesInQueue(queue))})
 	}
 	if shouldInclude("CreatedTimestamp") {
-		queueAttributes = append(queueAttributes, models.Attribute{Name: "CreatedTimestamp", Value: "0000000000"})
+		queueAttributes = append(queueAttributes, models.Attribute{Name: "CreatedTimestamp", Value: epochSeconds(queue.CreatedAt)})
 	}
 	if shouldInclude("LastModifiedTimestamp") {
-		queueAttributes = append(queueAttributes, models.Attribute{Name: "LastModifiedTimestamp", Value: "0000000000"})
+		queueAttributes = append(queueAttributes, models.Attribute{Name: "LastModifiedTimestamp", Value: epochSeconds(queue.LastModifiedAt)})
 	}
 	if shouldInclude("QueueArn") {
 		queueAttributes = append(queueAttributes, models.Attribute{Name: "QueueArn", Value: queue.Arn})
@@ -107,6 +115,10 @@ func GetQueueAttributesV1(req *http.Request) (int, interfaces.AbstractResponseBo
 			Value: fmt.Sprintf(`{"maxReceiveCount":"%d", "deadLetterTargetArn":"%s"}`, queue.MaxReceiveCount, queue.DeadLetterQueue.Arn),
 		})
 	}
+	// Policy — отдаём сохранённую JSON-строку как есть (совместимость с Terraform).
+	if shouldInclude("Policy") && queue.Policy != "" {
+		queueAttributes = append(queueAttributes, models.Attribute{Name: "Policy", Value: queue.Policy})
+	}
 
 	respStruct := models.GetQueueAttributesResponse{
 		Xmlns:    models.BaseXmlns,
@@ -115,3 +127,12 @@ func GetQueueAttributesV1(req *http.Request) (int, interfaces.AbstractResponseBo
 	}
 	return http.StatusOK, respStruct
 }
+
+// epochSeconds — timestamp в формате AWS (unix-секунды строкой).
+// Нулевое время отдаём как "0" (стабильно, без drift при чтении).
+func epochSeconds(t time.Time) string {
+	if t.IsZero() {
+		return "0"
+	}
+	return strconv.FormatInt(t.Unix(), 10)
+}