Add local vs R2 destination picker for admin asset uploads; v2.0.39

Upload dropdown lets you choose R2 folder (uploads/images/guides/finished)
or local server disk. Asset table shows location column for each file.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -1,7 +1,7 @@
 {
   "name": "siteforge",
   "private": true,
-  "version": "2.0.38",
+  "version": "2.0.39",
   "type": "module",
   "scripts": {
     "dev": "vite",