fix(update): resolve template path when updating to a different base model (#1059)

Version-tab updates reused the current version's folder, so updating a LoRA
to a version with a different base model (e.g. Illustrious -> Anima) ignored
the download path template and landed in the old version's directory.

When the target version's base model differs from the current local version
and a path template is configured, re-resolve the template under the same
model root. The backend keeps an explicitly provided root when
use_save_dir_as_root is set, so regular downloads still use the default root.

static/js/api/baseModelApi.js

@@ -1233,7 +1233,7 @@ export class BaseModelApiClient {
         }
     }
 
-    async downloadModel(modelId, versionId, modelRoot, relativePath, useDefaultPaths = false, downloadId, source = null, fileParams = null) {
+    async downloadModel(modelId, versionId, modelRoot, relativePath, useDefaultPaths = false, downloadId, source = null, fileParams = null, useSaveDirAsRoot = false) {
         try {
             const response = await fetch(DOWNLOAD_ENDPOINTS.download, {
                 method: 'POST',
@@ -1244,6 +1244,7 @@ export class BaseModelApiClient {
                     model_root: modelRoot,
                     relative_path: relativePath,
                     use_default_paths: useDefaultPaths,
+                    use_save_dir_as_root: useSaveDirAsRoot,
                     download_id: downloadId,
                     ...(source ? { source } : {}),
                     ...(fileParams ? { file_params: fileParams } : {})