docs: migrate legacy docs to official site

docs/guide/trash.md

@@ -9,12 +9,21 @@ OxiCloud provides a trash system that soft-deletes files and folders, allowing u
 3. Users can browse the trash, restore items, or permanently delete them
 4. Items older than the retention period (default: **30 days**) are automatically purged
 
+## Storage Model
+
+- files and folders keep their original rows in PostgreSQL
+- deletion into trash only flips soft-delete state and records the original parent location for restore
+- blob content is not moved when an item enters the trash
+- the unified `storage.trash_items` view is used to list trashed files and folders together
+
 ## API Endpoints
 
 | Method | Endpoint | Description |
 |--------|----------|-------------|
 | GET | `/api/trash` | List trashed items |
-| POST | `/api/trash/restore/{id}` | Restore a trashed item |
+| DELETE | `/api/trash/files/{id}` | Move a file to the trash |
+| DELETE | `/api/trash/folders/{id}` | Move a folder to the trash |
+| POST | `/api/trash/{id}/restore` | Restore a trashed item |
 | DELETE | `/api/trash/{id}` | Permanently delete |
 | DELETE | `/api/trash/empty` | Empty the entire trash |
 
@@ -25,3 +34,5 @@ Permanent deletion decrements the blob reference count. If no other file points
 ## Feature Flag
 
 Trash can be disabled via `OXICLOUD_ENABLE_TRASH=false`. When disabled, deletions are permanent.
+
+Retention is controlled by `OXICLOUD_TRASH_RETENTION_DAYS`.