fix: add missing libraryService.js and fix two bugs

- Create missing src/services/libraryService.js (was imported but never created)
- Fix readJSONFile import in tagIndexer.js (unused import)
- Fix found.found?.libId typo in deleteDocument (double .found lookup)

These were blocking the application from starting.

src/services/documentService.js

@@ -276,7 +276,6 @@ export class DocumentService {
     }
 
     const meta = readJSON(found.metaPath);
-    deletePath(found.found?.libId ? join(this.librariesPath, found.libId, 'documents', docId) : null);
     deletePath(this._docPath(found.libId, docId));
 
     this.tagIndexer.removeDocument(docId);