fix(upload): 分片上传 - 先预留配额并原子提交容量 (#679)

Co-authored-by: ddcat666 <26564566+ddcat666@users.noreply.github.com>

backend/internal/app/chunk_quota_security_test.go

@@ -0,0 +1,58 @@
+package app
+
+import (
+	"bytes"
+	"testing"
+	"time"
+)
+
+func TestChunkQuotaRejectsSingleFileLimit(t *testing.T) {
+	svc := newResourceTestService(t)
+	if _, err := svc.reserveChunkedUploadQuota("user-1", megabytes(defaultRuntimePolicy().Resource.ResourceUploadMB)); err == nil {
+		t.Fatal("chunked upload accepted a file at the exclusive single-file limit")
+	}
+}
+
+func TestChunkQuotaReservedUploadConsumesOnce(t *testing.T) {
+	svc := newResourceTestService(t)
+	if err := svc.ReserveChunkUploadSession("user", "session", 7, time.Now().Add(time.Hour), 32); err != nil {
+		t.Fatal(err)
+	}
+	day := time.Now().UTC().Format("2006-01-02")
+	if used, _ := svc.repo.DailyUploadBytes("user", day); used != 7 {
+		t.Fatalf("quota before receiving bytes=%d", used)
+	}
+	resource, err := svc.UploadReservedResourceFile("user", "session", "test.txt", 7, "file", 0, 0, 0, bytes.NewReader([]byte("payload")), "logical-key")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if resource.Size != 7 {
+		t.Fatalf("size=%d", resource.Size)
+	}
+	if used, _ := svc.repo.DailyUploadBytes("user", day); used != 7 {
+		t.Fatalf("quota after completion=%d", used)
+	}
+	if err := svc.ReserveChunkUploadSession("user", "retry", 7, time.Now().Add(time.Hour), 32); err != nil {
+		t.Fatal(err)
+	}
+	reused, err := svc.UploadReservedResourceFile("user", "retry", "test.txt", 7, "file", 0, 0, 0, bytes.NewReader([]byte("payload")), "logical-key")
+	if err != nil || reused.ID != resource.ID {
+		t.Fatalf("retry=%v err=%v", reused, err)
+	}
+	if used, _ := svc.repo.DailyUploadBytes("user", day); used != 7 {
+		t.Fatalf("quota after replay=%d", used)
+	}
+}
+
+func TestChunkQuotaFailedCompletionReleases(t *testing.T) {
+	svc := newResourceTestService(t)
+	if err := svc.ReserveChunkUploadSession("user", "failed", 7, time.Now().Add(time.Hour), 32); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := svc.UploadReservedResourceFile("user", "failed", "test.txt", 7, "file", 0, 0, 0, nil); err == nil {
+		t.Fatal("nil file accepted")
+	}
+	if used, _ := svc.repo.DailyUploadBytes("user", time.Now().UTC().Format("2006-01-02")); used != 0 {
+		t.Fatalf("failed upload retained quota=%d", used)
+	}
+}