Function uploadReference

web/app.js:1716–1760

(file, confirmBtn, previewEl, statusEl)

  }

  async function uploadReference(file, confirmBtn, previewEl, statusEl) {
    if (!file.type.startsWith("image/")) {
      statusEl.textContent = t("upload.only_images");
      return null;
    }

    confirmBtn.disabled = true;
    statusEl.textContent = t("upload.uploading");

    const formData = new FormData();
    formData.append("file", file);

    try {
      const response = await fetch("/api/upload", {
        method: "POST",
        body: formData,
      });

      if (!response.ok) {
        const text = await response.text();
        throw new Error(text || "Upload failed");
      }

      const data = await response.json();
      const isImport = statusEl?.id === "importFigureStatus";
      statusEl.textContent = t(
        isImport ? "upload.uploaded_stage1" : "upload.uploaded_reference",
        { name: data.name }
      );
      if (previewEl) {
        previewEl.src = data.url || "";
        previewEl.classList.add("visible");
      }
      return {
        path: data.path || null,
        url: data.url || "",
        name: data.name || "",
      };
    } catch (err) {
      statusEl.textContent = err.message || t("upload.upload_failed");
      return null;
    } finally {
      confirmBtn.disabled = false;
    }
  }

  async function initCanvasPage() {
    const params = new URLSearchParams(window.location.search);