Files: sturdier Seafile pass-through (timeouts, retries, stop on disconnect), in-place sign-in, saved folder lists, upload name clashes, undo and recycle bin, library search, zip downloads, share link options, text viewer and editor

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.gitea/workflows/build.yml

@@ -27,6 +27,7 @@ jobs:
       - run: node tools/lyrics-test.js  # lyrics: formats, wrong matches refused, remembered
       - run: node tools/mail-test.js    # Outlook.com mail through Microsoft Graph: connect, refresh, read, send, privacy
       - run: node tools/mail-imap-test.js # Gmail and iCloud mail over IMAP/SMTP: connect, read, send, reply, privacy
+      - run: node tools/files-test.js   # the Seafile pass-through: timeouts, retries, closed downloads, uploads
       - run: node tools/signal-test.js  # Signal: linking, messages, sending, live updates
 
       - uses: docker/setup-qemu-action@v3