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>

src/App.tsx

@@ -12,6 +12,7 @@ import { usePageMeta } from './hooks/usePageMeta'
 import { useGlobalSearch } from './hooks/useGlobalSearch'
 import { GlobalSearch } from './components/GlobalSearch'
 import { EpisodeAudioPlayer } from './components/EpisodeAudioPlayer'
+import { NuggetsHostPortal } from './components/NuggetsHostPortal'
 import { BIBLE_BOOKS } from '../shared/bible-books.js'
 import './App.css'
 import { sendEvent, useScrollDepthTracking, useTimeOnPage, useUTMCapture, useLinkClickTracking } from './analytics'
@@ -3139,6 +3140,7 @@ export default function App() {
       <Route path="/subscribe" element={<SubscribePage />} />
       <Route path="/subscribe/thanks" element={<SubscribeThankYouPage />} />
       <Route path="/certificate/:token" element={<PublicCertificatePage />} />
+      <Route path="/host-upload" element={<NuggetsHostPortal />} />
       <Route path="/admin" element={<AdminShell content={content} onSave={setContent} />} />
       <Route path="/preview" element={<PreviewPage />} />
       <Route