WebDAV Backup and Automatic Synchronization

Periodically back up accounts and preferences via a WebDAV server to enable multi-device sharing, version rollback, and disaster recovery.

Feature Highlights

One-Click Backup/Restore: After filling in WebDAV credentials on the "Import/Export" page, you can upload or download JSON backups at any time.
Automatic Synchronization: webdavAutoSyncService supports scheduled background synchronization (default 1 hour), automatically merging or overwriting data based on the strategy.
Multi-Strategy Support: Choose "Merge / Upload Only / Download Only" to meet differentiated needs for primary and secondary devices.
Conflict Merging: In merge mode, accounts and preferences are de-duplicated by update time, maximizing the retention of newer data.

Prepare an accessible WebDAV server: e.g., Nextcloud, Nutstore, Alist WebDAV, NAS, etc.
Obtain URL / Username / Password, ensuring read/write permissions.
If automatic synchronization is required, it is recommended to keep the browser running in the background (desktop Chrome/Edge or mobile Kiwi).

Open Extension → Import/Export → "WebDAV Settings".
Fill in:
- Server Address: Can point to a directory or a specific JSON file; if a directory is entered, all-api-hub-backup/all-api-hub-1-0.json will be automatically created under it.
- Username/Password: Used for Basic Auth.
Click "Test Connection" to verify the configuration, then you can perform "Upload Backup" or "Download Backup".

Enable "Automatic Synchronization" on the same page for scheduled background synchronization:

Option	Description
Enable Automatic Sync	Corresponds to the `webdav.autoSync` switch; when off, only manual backups are retained.
Sync Interval	In seconds, default 3600 seconds (1 hour).
Sync Strategy	`merge` (merge), `upload_only` (local overwrites remote), `download_only` (remote overwrites local).
Sync Now	Triggers `webdavAutoSync:syncNow` for debugging; if synchronization is in progress, it will prompt to try again later.

After the user saves settings, webdavAutoSyncService.setupAutoSync() will recreate the setInterval timer.
When synchronization is performed:
- First call testWebdavConnection to confirm credentials are valid.
- Download remote backup (if it doesn't exist, it's considered the first backup).
- Export local accounts and preferences, determining the final data based on the strategy:
  - Merge: Retain the latest items based on updated_at / lastUpdated timestamps.
  - Upload Only/Download Only: Directly select local or remote data.
- Write the merged result back to local (via accountStorage.importData + userPreferences.importPreferences).
- Generate new JSON and upload it to all-api-hub-backup/all-api-hub-1-0.json.
Synchronization status (success/failure, last execution time) will be broadcast via the WEBDAV_AUTO_SYNC_UPDATE message, which can be monitored on the frontend or viewed in console logs.

It is recommended to create a separate sub-account or access token for the backup directory on the WebDAV server.
Do not save WebDAV passwords on public devices, and change them regularly if necessary.
If synchronization fails with a 401/403 error, please confirm that the server supports Basic Auth and allows MKCOL/PUT/GET methods.

Issue	Solution
Test connection failed	Check if the URL includes the protocol (`https://`) and if remote writing is allowed.
Automatic synchronization unresponsive	Possibly due to the browser being put to sleep by the system or automatic synchronization not being enabled; reopen the extension and save settings.
Duplicate accounts after merging	Manually delete duplicates and re-upload; for strict control, use the "Upload Only" strategy.
JSON file too large	It is recommended to regularly clean up expired accounts or export in batches to avoid exceeding WebDAV limits.