feat(deploy): 在线更新 - 新增后台检查、强制备份迁移与失败自动回退

backend/internal/buildinfo/buildinfo_test.go

@@ -0,0 +1,17 @@
+package buildinfo
+
+import "testing"
+
+func TestCurrentUsesInjectedValues(t *testing.T) {
+	previousVersion, previousCommit, previousBuildTime := Version, Commit, BuildTime
+	t.Cleanup(func() { Version, Commit, BuildTime = previousVersion, previousCommit, previousBuildTime })
+	Version, Commit, BuildTime = " v1.2.3 ", " abc123 ", " 2026-08-30T00:00:00Z "
+
+	info := Current()
+	if info.Version != "v1.2.3" || info.Commit != "abc123" || info.BuildTime != "2026-08-30T00:00:00Z" {
+		t.Fatalf("unexpected build info: %#v", info)
+	}
+	if info.GoVersion == "" {
+		t.Fatal("Go version should be populated")
+	}
+}