test(s3/lifecycle): integration coverage for ObjectSizeGreaterThan filter

ObjectSizeGreaterThan is a strict > gate (filterAllows uses
ev.Size <= rule.FilterSizeGreaterThan to reject). Pinned at the
boundary: an object whose size equals the threshold must remain;
only an object strictly larger expires. Catches a > vs >= flip.

Two backdated objects on the same prefix, sizes 100 and 150 with
threshold=100 — boundary survives, larger expires.

test/s3/lifecycle/s3_lifecycle_size_filter_test.go

@@ -0,0 +1,71 @@
+// Size-filter integration scenario.
+package lifecycle
+
+import (
+	"context"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/service/s3"
+	"github.com/aws/aws-sdk-go-v2/service/s3/types"
+	"github.com/stretchr/testify/require"
+)
+
+// TestLifecycleSizeFilterGreaterThan: ObjectSizeGreaterThan is a strict >
+// gate (filterAllows in match.go uses ev.Size <= rule.FilterSizeGreaterThan
+// to reject). Two backdated objects on the same prefix — only the one
+// strictly larger than the threshold is expired.
+func TestLifecycleSizeFilterGreaterThan(t *testing.T) {
+	c := s3Client(t)
+	fc, fcClose := filerClient(t)
+	defer fcClose()
+
+	bucket := uniqueBucket("size-filter")
+	mustCreateBucket(t, c, bucket)
+
+	const threshold = 100
+	_, err := c.PutBucketLifecycleConfiguration(context.Background(), &s3.PutBucketLifecycleConfigurationInput{
+		Bucket: aws.String(bucket),
+		LifecycleConfiguration: &types.BucketLifecycleConfiguration{
+			Rules: []types.LifecycleRule{{
+				ID:     aws.String("size-gt"),
+				Status: types.ExpirationStatusEnabled,
+				Filter: &types.LifecycleRuleFilter{
+					And: &types.LifecycleRuleAndOperator{
+						Prefix:                  aws.String("sz/"),
+						ObjectSizeGreaterThan: aws.Int64(threshold),
+					},
+				},
+				Expiration: &types.LifecycleExpiration{Days: aws.Int32(1)},
+			}},
+		},
+	})
+	require.NoError(t, err)
+
+	const smallKey = "sz/small.txt"  // size <= threshold → must remain
+	const largeKey = "sz/large.txt"  // size > threshold → must expire
+	putObject(t, c, bucket, smallKey, strings.Repeat("a", threshold)) // exactly at boundary; gate is strictly >, so rejects
+	putObject(t, c, bucket, largeKey, strings.Repeat("a", threshold+50))
+
+	backdateMtime(t, fc, bucket, smallKey, 30)
+	backdateMtime(t, fc, bucket, largeKey, 30)
+
+	out := runLifecycleShard(t)
+	t.Logf("shell output:\n%s", out)
+
+	// Larger-than-threshold object expired.
+	require.Eventuallyf(t, func() bool {
+		_, err := c.HeadObject(context.Background(), &s3.HeadObjectInput{
+			Bucket: aws.String(bucket), Key: aws.String(largeKey),
+		})
+		return err != nil
+	}, 30*time.Second, 500*time.Millisecond, "object larger than threshold must expire")
+
+	// Boundary object (size == threshold) survives — strictly-greater gate.
+	_, err = c.HeadObject(context.Background(), &s3.HeadObjectInput{
+		Bucket: aws.String(bucket), Key: aws.String(smallKey),
+	})
+	require.NoError(t, err, "object at exact threshold must remain (gate is strictly >)")
+}