Add Nuggets host upload portal with Seafile integration; v2.0.4

- New /host-upload page: per-host login (username + password) with
  session cookie, drag-and-drop file upload to Seafile via server proxy
- Two upload targets: Episode Upload (audio) and Episode Info (docs)
- Server route: /api/nuggets-upload/* for host auth + file proxy,
  /api/admin/nuggets-upload/hosts for admin CRUD (create/disable/reset pw/delete)
- Admin panel: Nuggets → Upload Portal view to manage host accounts
- Seafile config via SEAFILE_URL / SEAFILE_TOKEN / SEAFILE_NUGGETS_REPO_ID env vars
- Directories default to /Episode Upload and /Episode Info (configurable)
- Uses multer for multipart uploads; 500 MB per-file limit

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

package.json

@@ -1,7 +1,7 @@
 {
   "name": "siteforge",
   "private": true,
-  "version": "2.0.3",
+  "version": "2.0.4",
   "type": "module",
   "scripts": {
     "dev": "vite",
@@ -24,6 +24,7 @@
     "express-rate-limit": "^8.4.1",
     "fuse.js": "^7.4.2",
     "mammoth": "^1.12.0",
+    "multer": "^2.3.0",
     "otplib": "^13.4.0",
     "prop-types": "^15.8.1",
     "qrcode": "^1.5.4",