bugfix/thumbnails on update

Bug 1 & 2 (webdav_handler.rs handle_put() update branch):
  - After a successful file update via WebDAV PUT, if the content type is a supported image:
    a. delete_thumbnails(file_id) — evicts the stale moka cache entry
    b. Spawns a background task to read the new blob bytes and call generate_all_sizes_background_from_bytes

  Bug 3 & 4 (dedup_service.rs):
  - Added thumbnail_service: Option<Arc<ThumbnailService>> field with a with_thumbnail_service() builder
  - In remove_legacy_reference(): calls delete_blob_thumbnails(hash) when ref_count hits 0
  - In remove_manifest_reference(): calls delete_blob_thumbnails(file_hash) when manifest's last ref is dropped
  - Wired in di.rs — the thumbnail service is created before dedup service so the ordering works cleanly

src/interfaces/api/handlers/webdav_handler.rs

@@ -972,6 +972,15 @@ async fn handle_put(
                 );
             }
 
+            state
+                .core
+                .refresh_thumbnails_after_update(
+                    file_dto.id.clone(),
+                    file_dto.etag.clone(),
+                    &content_type,
+                )
+                .await;
+
             Ok(Response::builder()
                 .status(StatusCode::NO_CONTENT)
                 .body(Body::empty())

src/interfaces/api/handlers/wopi_handler.rs

@@ -288,7 +288,19 @@ async fn put_file(
     let _ = tokio::fs::remove_file(&temp_path).await;
 
     match result {
-        Ok(_) => StatusCode::OK.into_response(),
+        Ok(file_dto) => {
+            state
+                .app_state
+                .core
+                .refresh_thumbnails_after_update(
+                    file_dto.id.clone(),
+                    file_dto.etag.clone(),
+                    &content_type,
+                )
+                .await;
+
+            StatusCode::OK.into_response()
+        }
         Err(e) => {
             tracing::error!("WOPI PutFile failed: {}", e);
             StatusCode::INTERNAL_SERVER_ERROR.into_response()