The Nextcloud Android client compares ETags before and after upload to
verify its write landed. OxiCloud was returning the stable file UUID as
the ETag, which never changed on content updates, causing false
SYNC_CONFLICT errors on every upload.
Five fixes applied:
1. Thread blob_hash (SHA-256) through File entity, FileDto, all read/write
queries, and all WebDAV/PROPFIND responses as the ETag — changes on
every content update, no DB migration needed.
2. Honor X-OC-Mtime header: parse the client-supplied mtime and use it
for updated_at via COALESCE(to_timestamp($n), NOW()).
3. Disable phantom checksum capability (preferredUploadType/supportedTypes)
that the server never actually implemented, stopping retry loops.
4. Add nc:creation_time and nc:upload_time to PROPFIND responses.
5. Return oc-etag header in chunked upload MOVE (assemble) responses.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Implement a complete Nextcloud client compatibility layer so that
Nextcloud desktop/mobile sync clients can connect to OxiCloud.
Key additions:
- Login Flow v2 (device auth) with OIDC bridge support
- WebDAV handler compatible with Nextcloud clients (PROPFIND, GET,
PUT, DELETE, MKCOL, MOVE, COPY, HEAD, PROPPATCH)
- OCS API endpoints (user info, capabilities, notifications stubs,
sharees, unified search)
- Basic Auth middleware with app password verification, account
lockout integration, and blake3-keyed auth cache
- App password management: create, list, revoke via both native
API (JWT-authenticated profile page) and Nextcloud OCS endpoints
- Nextcloud file ID mapping (oc:fileid) with persistent DB storage
- Chunked upload support (Nextcloud v2 chunking protocol)
- Trashbin WebDAV interface
- Avatar (SVG placeholder) and preview (redirect) handlers
- User profile page with app password management UI
- URL user validation on all DAV routes (403 on mismatch)
- Database schema for app_passwords and nextcloud_object_ids tables
All services are behind a `nextcloud.enabled` config flag and
cleanly separated under src/interfaces/nextcloud/.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>