Add image name input to cloud-init build process and update handling

Enhance the dashboard UI by introducing an optional input field for the image name in the cloud-init build form. Update the API to process the image name, ensuring it is sanitized and included in the build request. Modify the build script to utilize the provided image name, allowing for customized output filenames during the image creation process. This improves user experience by offering more flexibility in naming cloud-init images.

emmc-provisioning/dashboard/app.py

@@ -1636,12 +1636,15 @@ def api_build_cloudinit():
     meta_data = body.get("meta_data") or DEFAULT_META_DATA
     network_config = body.get("network_config") or DEFAULT_NETWORK_CONFIG
     set_as_golden_after = bool(body.get("set_as_golden_after"))
+    image_name = (body.get("image_name") or "").strip()[:64]
+    image_name = re.sub(r"[^\w\-]", "", image_name)  # only alphanumeric, underscore, dash
     try:
         BUILD_REQUEST_FILE.parent.mkdir(parents=True, exist_ok=True)
         with open(BUILD_REQUEST_FILE, "w") as f:
             json.dump({
                 "url": url,
                 "variant": variant,
+                "image_name": image_name or None,
                 "user_data": user_data,
                 "meta_data": meta_data,
                 "network_config": network_config,