feat(nextcloud): add Nextcloud-compatible API layer

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>

src/application/services/batch_operations.rs

@@ -1042,18 +1042,22 @@ impl BatchOperationService {
 #[cfg(integration_tests)]
 mod tests {
     use super::*;
-    use crate::common::stubs::{StubFileManagementUseCase, StubFileRetrievalUseCase};
+    use crate::infrastructure::repositories::pg::file_blob_read_repository::FileBlobReadRepository;
+    use crate::infrastructure::repositories::pg::file_blob_write_repository::FileBlobWriteRepository;
+    use crate::infrastructure::repositories::pg::folder_db_repository::FolderDbRepository;
     use std::sync::Arc;
 
     #[tokio::test]
     async fn test_generic_batch_operation() {
-        // Create the batch service with stubs
+        // Create the batch service with stub repositories (lazy pool — no SQL is executed
+        // in this test; generic_batch_operation never touches file/folder services).
+        let folder_repo = Arc::new(FolderDbRepository::new_stub());
+        let file_read_repo = Arc::new(FileBlobReadRepository::new_stub());
+        let file_write_repo = Arc::new(FileBlobWriteRepository::new_stub());
         let batch_service = BatchOperationService::new(
-            Arc::new(StubFileRetrievalUseCase),
-            Arc::new(StubFileManagementUseCase),
-            Arc::new(FolderService::new(Arc::new(
-                crate::common::stubs::StubFolderStoragePort,
-            ))),
+            Arc::new(FileRetrievalService::new(file_read_repo)),
+            Arc::new(FileManagementService::new(file_write_repo)),
+            Arc::new(FolderService::new(folder_repo)),
             AppConfig::default(),
         );