Replace empty arrow functions with explicit comments

Updated all empty arrow functions and constructors to include an explicit '/* empty */' comment for clarity and consistency. Also fixed a minor HTML entity in SwaggerUI and removed unnecessary async/Promise usage in some service methods.

frontend/src/components/shared/fitText/textFit.ts

@@ -21,7 +21,7 @@ export function adjustFontSizeToFit(
   element: HTMLElement,
   options: AdjustFontSizeOptions = {}
 ): () => void {
-  if (!element) return () => {};
+  if (!element) return () => { /* empty */ };
 
   const computed = window.getComputedStyle(element);
   const baseFontPx = options.maxFontSizePx ?? parseFloat(computed.fontSize || '16');

frontend/src/components/tools/automate/ToolSelector.tsx

@@ -150,7 +150,7 @@ export default function ToolSelector({
           <div onClick={handleSearchFocus} style={{ cursor: 'pointer',
            borderRadius: "var(--mantine-radius-lg)" }}>
             <ToolButton id='tool' tool={toolRegistry[selectedValue]}  isSelected={false}
-          onSelect={()=>{}} rounded={true} disableNavigation={true}></ToolButton>
+          onSelect={()=>{ /* empty */ }} rounded={true} disableNavigation={true}></ToolButton>
           </div>
         ) : (
           // Show search input when no tool selected OR when dropdown is opened

frontend/src/contexts/file/fileHooks.ts

@@ -166,9 +166,9 @@ export function useFileContext() {
     addFiles: actions.addFiles,
     consumeFiles: actions.consumeFiles,
     undoConsumeFiles: actions.undoConsumeFiles,
-    recordOperation: (_fileId: FileId, _operation: any) => {}, // Operation tracking not implemented
-    markOperationApplied: (_fileId: FileId, _operationId: string) => {}, // Operation tracking not implemented
-    markOperationFailed: (_fileId: FileId, _operationId: string, _error: string) => {}, // Operation tracking not implemented
+    recordOperation: (_fileId: FileId, _operation: any) => { /* empty */ }, // Operation tracking not implemented
+    markOperationApplied: (_fileId: FileId, _operationId: string) => { /* empty */ }, // Operation tracking not implemented
+    markOperationFailed: (_fileId: FileId, _operationId: string, _error: string) => { /* empty */ }, // Operation tracking not implemented
     // File ID lookup
     findFileId: (file: File) => {
       return state.files.ids.find(id => {

frontend/src/hooks/tools/adjustPageScale/useAdjustPageScaleParameters.test.ts

@@ -57,7 +57,7 @@ describe('useAdjustPageScaleParameters', () => {
   test.each([
     {
       description: 'with default parameters',
-      setup: () => {},
+      setup: () => { /* empty */ },
       expected: true
     },
     {

frontend/src/hooks/useFileWithUrl.ts

@@ -40,7 +40,7 @@ export function useFileWithUrlAndCleanup(file: File | null): {
   cleanup: () => void;
 } {
   return useMemo(() => {
-    if (!file) return { fileObj: null, cleanup: () => {} };
+    if (!file) return { fileObj: null, cleanup: () => { /* empty */ } };
 
     const url = URL.createObjectURL(file);
     const fileObj = { file, url };

frontend/src/hooks/useToolParameters.ts

@@ -16,7 +16,7 @@ export function useToolParameters(
 
   // Return empty values and noop updater
   const currentValues = useMemo(() => ({}), []);
-  const updateParameters = useCallback(() => {}, []);
+  const updateParameters = useCallback(() => { /* empty */ }, []);
 
   return [currentValues, updateParameters];
 }
@@ -45,7 +45,7 @@ export function useToolParameter<T = any>(
  */
 export function useGlobalParameters() {
   const currentValues = useMemo(() => ({}), []);
-  const updateParameters = useCallback(() => {}, []);
+  const updateParameters = useCallback(() => { /* empty */ }, []);
 
   return [currentValues, updateParameters];
 }

frontend/src/services/enhancedPDFProcessingService.ts

@@ -29,7 +29,7 @@ export class EnhancedPDFProcessingService {
     maxRetries: 3
   };
 
-  private constructor() {}
+  private constructor() { /* empty */ }
 
   static getInstance(): EnhancedPDFProcessingService {
     if (!EnhancedPDFProcessingService.instance) {

frontend/src/services/indexedDBManager.ts

@@ -24,7 +24,7 @@ class IndexedDBManager {
   private databases = new Map<string, IDBDatabase>();
   private initPromises = new Map<string, Promise<IDBDatabase>>();
 
-  private constructor() {}
+  private constructor() { /* empty */ }
 
   static getInstance(): IndexedDBManager {
     if (!IndexedDBManager.instance) {

frontend/src/services/pdfExportService.ts

@@ -210,7 +210,7 @@ export class PDFExportService {
   /**
    * Download multiple files as a ZIP
    */
-  async downloadAsZip(blobs: Blob[], filenames: string[]): Promise<void> {
+  downloadAsZip(blobs: Blob[], filenames: string[]): void {
     blobs.forEach((blob, index) => {
       setTimeout(() => {
         this.downloadFile(blob, filenames[index]);

frontend/src/services/pdfProcessingService.ts

@@ -9,7 +9,7 @@ export class PDFProcessingService {
   private processing = new Map<string, ProcessingState>();
   private processingListeners = new Set<(states: Map<string, ProcessingState>) => void>();
 
-  private constructor() {}
+  private constructor() { /* empty */ }
 
   static getInstance(): PDFProcessingService {
     if (!PDFProcessingService.instance) {
@@ -18,7 +18,7 @@ export class PDFProcessingService {
     return PDFProcessingService.instance;
   }
 
-  async getProcessedFile(file: File): Promise<ProcessedFile | null> {
+  getProcessedFile(file: File): ProcessedFile | null {
     const fileKey = this.generateFileKey(file);
 
     // Check cache first

frontend/src/tools/SwaggerUI.tsx

@@ -12,7 +12,7 @@ const SwaggerUI: React.FC<BaseToolProps> = () => {
     <div style={{ textAlign: "center", padding: "2rem" }}>
       <p>Opening Swagger UI in a new tab...</p>
       <p>
-        If it didn't open automatically,{" "}
+        If it didn&apos;t open automatically,{" "}
         <a href={withBasePath("/swagger-ui/5.21.0/index.html")} target="_blank" rel="noopener noreferrer">
           click here
         </a>