feat: add per-user trash (soft delete) with scheduled cleanup

[GabrielBBaldez]

What

Implements the per-user trash described in #60:

• Delete moves to trash — DELETE /api/files now moves the file into a per-user trash instead of removing it permanently.
• Restore / permanent delete — new endpoints under /api/files/trash: list, restore (back to the original path), and permanent delete.
• Auto-purge after 30 days — a scheduled job removes entries once their retention period elapses.

How

• TrashEntry (+ TrashEntryRepository) persists the trash metadata (original path, deleted-at, size). The file itself is moved into a hidden .trash directory under the user's root, so it stays within the existing validatePath security boundary; .trash is excluded from folder listings and search.
• TrashService handles move / list / restore / purge and the scheduled cleanup (@Scheduled, enabled via @EnableScheduling). Both are configurable: cloudpage.trash.retention-days (default 30) and cloudpage.trash.cleanup-cron (default daily at 03:00).
• The trash_entries table is created automatically (ddl-auto=update).

Design notes / open question

• Trashed files currently still count toward the storage quota until they are purged — happy to change this if you'd prefer they don't.
• The case you raised in the issue — files removed directly on disk (OS file explorer) rather than through Vault Web — is not handled here. I left it as a follow-up since it needs a filesystem-watching / reconciliation approach and your steer on the direction.

Testing

• New TrashServiceTest: move-to-trash, restore, permanent delete, scheduled purge of expired entries, and not-found handling.
• Full backend suite green locally — 98 tests, 0 failures — plus spotless:check and verify.

Closes #60

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds a per-user “trash” (soft-delete) feature: deleted files are moved to a hidden .trash directory, tracked in DB, restorable/purgeable via API, and automatically cleaned up on a schedule.

Changes:

• Introduces TrashService, TrashEntry (entity), TrashEntryRepository, and TrashController endpoints for listing/restore/purge.
• Updates file deletion to move files to trash instead of permanently deleting them.
• Excludes .trash from folder listing/search and enables scheduling for retention-based cleanup; adds unit tests for TrashService.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
backend/src/main/java/cloudpage/service/TrashService.java	Implements soft-delete, restore, purge, and scheduled retention cleanup
backend/src/main/java/cloudpage/controller/TrashController.java	Adds REST endpoints for trash operations
backend/src/main/java/cloudpage/controller/FileController.java	Switches delete behavior to trash soft-delete
backend/src/main/java/cloudpage/service/FolderService.java	Filters .trash from listing/search results
backend/src/main/java/cloudpage/model/TrashEntry.java	Adds DB entity for trashed files metadata
backend/src/main/java/cloudpage/repository/TrashEntryRepository.java	Adds repository methods used by trash service
backend/src/main/java/cloudpage/dto/TrashEntryDto.java	Adds DTO for trash listing output
backend/src/main/java/cloudpage/Application.java	Enables scheduling for periodic purge
backend/src/test/java/cloudpage/service/TrashServiceTest.java	Adds tests for trash service behavior
backend/src/test/java/cloudpage/controller/FileControllerTest.java	Updates deletion test to assert soft-delete behavior

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[GabrielBBaldez]

Addressed the review feedback in the latest push:

• restore no longer overwrites a file that already exists at the original path — it throws instead of silently replacing it (avoids data loss if the file was recreated after deletion).
• If the DB write fails after the file is moved to the trash, the file is moved back — no orphaned trash files.
• .trash is now hidden only at the root, not for any folder named .trash deeper in the tree.
• The scheduled purge logs failures instead of swallowing them.
• Added TrashControllerTest covering the list / restore / permanent-delete endpoints.

[DenizAltunkapan]

Thanks @GabrielBBaldez would you like to integrate this in the frontend ui?

[GabrielBBaldez]

Pushed 6e215c5: restore now returns 409 Conflict (instead of a generic 500) when a file already exists at the original path — added a FileAlreadyExistsException handler in GlobalExceptionHandler plus a regression test. This gives the trash UI in Vault-Web/vault-web#238 a clean status to branch on.