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>

server/routes/admin-assets.js

@@ -37,10 +37,12 @@ export function register(app) {
       const filename = typeof req.body?.filename === 'string' ? req.body.filename : ''
       const dataUrl = typeof req.body?.dataUrl === 'string' ? req.body.dataUrl : ''
       const rawFolder = typeof req.body?.folder === 'string' ? req.body.folder : 'uploads'
+      const rawStorage = typeof req.body?.storage === 'string' ? req.body.storage : 'r2'
       const ext = inferImageExtensionFromDataUrl(dataUrl)
 
       const ALLOWED_FOLDERS = ['uploads', 'images', 'guides', 'finished']
       const folder = ALLOWED_FOLDERS.includes(rawFolder) ? rawFolder : 'uploads'
+      const useLocal = rawStorage === 'local' || !isR2Configured()
 
       if (!ext) {
         res.status(400).json({ message: 'Upload must be a PNG, JPG, WEBP, GIF, PDF, DOC, or DOCX data URL.' })
@@ -58,20 +60,20 @@ export function register(app) {
       const finalName = `${baseName}-${Date.now()}${ext}`
 
       let url
-      if (isR2Configured()) {
-        const contentType = dataUrl.match(/^data:([^;]+);base64,/)?.[1] ?? 'application/octet-stream'
-        url = await uploadToR2(buffer, `${folder}/${finalName}`, contentType)
-      } else {
+      if (useLocal) {
         await mkdir(UPLOADS_DIR, { recursive: true })
         await writeFile(path.join(UPLOADS_DIR, finalName), buffer)
         url = `/uploads/${finalName}`
+      } else {
+        const contentType = dataUrl.match(/^data:([^;]+);base64,/)?.[1] ?? 'application/octet-stream'
+        url = await uploadToR2(buffer, `${folder}/${finalName}`, contentType)
       }
 
       const metadata = await readUploadsMetadata()
-      metadata[finalName] = { tags: [], url, folder }
+      metadata[finalName] = { tags: [], url, folder: useLocal ? 'local' : folder }
       await writeUploadsMetadata(metadata)
 
-      res.json({ ok: true, asset: { filename: finalName, url, folder } })
+      res.json({ ok: true, asset: { filename: finalName, url, folder: useLocal ? 'local' : folder, storage: useLocal ? 'local' : 'r2' } })
     } catch (err) {
       console.error('[admin-assets] upload failed:', err)
       res.status(500).json({ message: 'Upload failed.' })