diff --git a/frontend/src/components/tools/addStamp/StampPreview.tsx b/frontend/src/components/tools/addStamp/StampPreview.tsx
index 730f36b35..a6a4c178b 100644
--- a/frontend/src/components/tools/addStamp/StampPreview.tsx
+++ b/frontend/src/components/tools/addStamp/StampPreview.tsx
@@ -72,7 +72,7 @@ export default function StampPreview({ parameters, onParameterChange, file, show
         if (!cancelled) setPageSize(null);
       }
     };
-    load();
+    void load();
     return () => { cancelled = true; };
   }, [file]);
 
@@ -88,12 +88,12 @@ export default function StampPreview({ parameters, onParameterChange, file, show
         const pageNumber = Math.max(1, getFirstSelectedPage(parameters.pageNumbers));
         const pageId = `${file.name}:${file.size}:${file.lastModified}:page:${pageNumber}`;
         const thumb = await requestThumbnail(pageId, file, pageNumber);
-        if (isActive) setPageThumbnail(thumb || null);
+        if (isActive) setPageThumbnail(thumb ?? null);
       } catch {
         if (isActive) setPageThumbnail(null);
       }
     };
-    loadThumb();
+    void loadThumb();
     return () => { isActive = false; };
   }, [file, parameters.pageNumbers, requestThumbnail]);
 
@@ -189,7 +189,7 @@ export default function StampPreview({ parameters, onParameterChange, file, show
 
     draggingRef.current = {
       type,
-      startX: e.clientX - (rect?.left || 0),
+      startX: e.clientX - (rect?.left ?? 0),
       startY: (rect ? rect.bottom - e.clientY : 0), // convert to bottom-based coords
       initLeft: left,
       initBottom: bottom,
@@ -255,11 +255,11 @@ export default function StampPreview({ parameters, onParameterChange, file, show
         <div className={styles.divider} />
         <div className={styles.previewLabel}>Preview Stamp</div>
       </div>
-      <div 
-        ref={containerRef} 
+      <div
+        ref={containerRef}
         className={`${styles.container} ${styles.containerBorder} ${pageThumbnail ? styles.containerWithThumbnail : styles.containerWithoutThumbnail}`}
-        style={style.container as React.CSSProperties} 
-        onPointerMove={handlePointerMove} 
+        style={style.container as React.CSSProperties}
+        onPointerMove={handlePointerMove}
         onPointerUp={handlePointerUp}
       >
         {pageThumbnail && (
diff --git a/frontend/src/components/tools/addStamp/useAddStampOperation.ts b/frontend/src/components/tools/addStamp/useAddStampOperation.ts
index c41c440fc..48480f408 100644
--- a/frontend/src/components/tools/addStamp/useAddStampOperation.ts
+++ b/frontend/src/components/tools/addStamp/useAddStampOperation.ts
@@ -7,7 +7,7 @@ export const buildAddStampFormData = (parameters: AddStampParameters, file: File
   const formData = new FormData();
   formData.append('fileInput', file);
   formData.append('pageNumbers', parameters.pageNumbers);
-  formData.append('customMargin', parameters.customMargin || 'medium'); 
+  formData.append('customMargin', parameters.customMargin || 'medium');
   formData.append('position', String(parameters.position));
   const effectiveFontSize = parameters.fontSize;
   formData.append('fontSize', String(effectiveFontSize));
@@ -19,7 +19,7 @@ export const buildAddStampFormData = (parameters: AddStampParameters, file: File
   formData.append('alphabet', parameters.alphabet);
 
   // Stamp type and payload
-  formData.append('stampType', parameters.stampType || 'text');
+  formData.append('stampType', parameters.stampType ?? 'text');
   if (parameters.stampType === 'text') {
     formData.append('stampText', parameters.stampText);
   } else if (parameters.stampType === 'image' && parameters.stampImage) {
diff --git a/frontend/src/components/tools/addWatermark/WatermarkImageFile.tsx b/frontend/src/components/tools/addWatermark/WatermarkImageFile.tsx
index 85e723ccb..90e603f52 100644
--- a/frontend/src/components/tools/addWatermark/WatermarkImageFile.tsx
+++ b/frontend/src/components/tools/addWatermark/WatermarkImageFile.tsx
@@ -17,7 +17,7 @@ const WatermarkImageFile = ({ parameters, onParameterChange, disabled = false }:
     <Stack gap="sm">
       <FileUploadButton
         file={parameters.watermarkImage}
-        onChange={(file) => onParameterChange('watermarkImage', file || undefined)}
+        onChange={(file) => onParameterChange('watermarkImage', file ?? undefined)}
         accept="image/*"
         disabled={disabled}
         placeholder={t('watermark.settings.image.choose', 'Choose Image')}
diff --git a/frontend/src/components/tools/addWatermark/WatermarkTypeSettings.tsx b/frontend/src/components/tools/addWatermark/WatermarkTypeSettings.tsx
index 2c7548df8..142d623a4 100644
--- a/frontend/src/components/tools/addWatermark/WatermarkTypeSettings.tsx
+++ b/frontend/src/components/tools/addWatermark/WatermarkTypeSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { useTranslation } from "react-i18next";
 import ButtonSelector from "../../shared/ButtonSelector";
 
diff --git a/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.test.tsx b/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.test.tsx
index d71655cdc..52b0abbd5 100644
--- a/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.test.tsx
+++ b/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.test.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { describe, expect, test, vi, beforeEach } from 'vitest';
 import { render, screen } from '@testing-library/react';
 import { MantineProvider } from '@mantine/core';
diff --git a/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.tsx b/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.tsx
index 9262bcba4..3879ad954 100644
--- a/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.tsx
+++ b/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, NumberInput, Select } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { AdjustPageScaleParameters, PageSize } from "../../../hooks/tools/adjustPageScale/useAdjustPageScaleParameters";
diff --git a/frontend/src/components/tools/automate/AutomationCreation.tsx b/frontend/src/components/tools/automate/AutomationCreation.tsx
index b5e793ccb..c19092f79 100644
--- a/frontend/src/components/tools/automate/AutomationCreation.tsx
+++ b/frontend/src/components/tools/automate/AutomationCreation.tsx
@@ -1,4 +1,4 @@
-import { useState } from 'react';
+import React, { useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import {
   Button,
@@ -100,7 +100,7 @@ export default function AutomationCreation({ mode, existingAutomation, onBack, o
       icon: automationIcon,
       operations: selectedTools.map(tool => ({
         operation: tool.operation,
-        parameters: tool.parameters || {}
+        parameters: tool.parameters ?? {}
       }))
     };
 
diff --git a/frontend/src/components/tools/automate/AutomationEntry.tsx b/frontend/src/components/tools/automate/AutomationEntry.tsx
index 30c280491..d68b517b5 100644
--- a/frontend/src/components/tools/automate/AutomationEntry.tsx
+++ b/frontend/src/components/tools/automate/AutomationEntry.tsx
@@ -240,7 +240,7 @@ export default function AutomationEntry({
   );
 
   // Show tooltip if there's a description OR operations to display
-  const shouldShowTooltip = description || operations.length > 0;
+  const shouldShowTooltip = description ?? operations.length > 0;
 
   return shouldShowTooltip ? (
     <Tooltip
diff --git a/frontend/src/components/tools/automate/AutomationRun.tsx b/frontend/src/components/tools/automate/AutomationRun.tsx
index 2d6bda6fc..d8f1e1a4e 100644
--- a/frontend/src/components/tools/automate/AutomationRun.tsx
+++ b/frontend/src/components/tools/automate/AutomationRun.tsx
@@ -26,7 +26,7 @@ export default function AutomationRun({ automation, onComplete, automateOperatio
   const [currentStepIndex, setCurrentStepIndex] = useState(-1);
 
   // Use the operation hook's loading state
-  const isExecuting = automateOperation?.isLoading || false;
+  const isExecuting = automateOperation?.isLoading ?? false;
   const hasResults = automateOperation?.files.length > 0 || automateOperation?.downloadUrl !== null;
 
   // Initialize execution steps from automation
@@ -194,7 +194,7 @@ export default function AutomationRun({ automation, onComplete, automateOperatio
           <Button
             leftSection={<PlayArrowIcon />}
             onClick={executeAutomation}
-            disabled={isExecuting || !selectedFiles || selectedFiles.length === 0}
+            disabled={(isExecuting ?? !selectedFiles) ?? selectedFiles.length === 0}
             loading={isExecuting}
           >
             {isExecuting
diff --git a/frontend/src/components/tools/automate/ToolConfigurationModal.tsx b/frontend/src/components/tools/automate/ToolConfigurationModal.tsx
index 4fce30b3d..ffac6a02d 100644
--- a/frontend/src/components/tools/automate/ToolConfigurationModal.tsx
+++ b/frontend/src/components/tools/automate/ToolConfigurationModal.tsx
@@ -1,4 +1,4 @@
-import { useState, useEffect } from 'react';
+import React, { useState, useEffect } from 'react';
 import { useTranslation } from 'react-i18next';
 import {
   Modal,
diff --git a/frontend/src/components/tools/automate/ToolSelector.tsx b/frontend/src/components/tools/automate/ToolSelector.tsx
index 7d5faafc5..33e43999f 100644
--- a/frontend/src/components/tools/automate/ToolSelector.tsx
+++ b/frontend/src/components/tools/automate/ToolSelector.tsx
@@ -1,4 +1,4 @@
-import { useState, useMemo, useCallback, useRef, useEffect } from 'react';
+import React, { useState, useMemo, useCallback, useRef, useEffect } from 'react';
 import { useTranslation } from 'react-i18next';
 import { Stack, Text, ScrollArea } from '@mantine/core';
 import { ToolRegistryEntry } from '../../../data/toolsTaxonomy';
@@ -82,7 +82,7 @@ export default function ToolSelector({
 
     // Find the "all" section which contains all tools without duplicates
     const allSection = sections.find(s => (s as any).key === 'all');
-    return allSection?.subcategories || [];
+    return allSection?.subcategories ?? [];
   }, [isSearching, searchGroups, sections, baseFilteredTools]);
 
   const handleToolSelect = useCallback((toolKey: string) => {
@@ -138,7 +138,7 @@ export default function ToolSelector({
     if (selectedValue && toolRegistry[selectedValue]) {
       return toolRegistry[selectedValue].name;
     }
-    return placeholder || t('automate.creation.tools.add', 'Add a tool...');
+    return placeholder ?? t('automate.creation.tools.add', 'Add a tool...');
   };
 
   return (
diff --git a/frontend/src/components/tools/certSign/CertificateFilesSettings.tsx b/frontend/src/components/tools/certSign/CertificateFilesSettings.tsx
index a11ba5b72..06610e5b4 100644
--- a/frontend/src/components/tools/certSign/CertificateFilesSettings.tsx
+++ b/frontend/src/components/tools/certSign/CertificateFilesSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Text, TextInput } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { CertSignParameters } from "../../../hooks/tools/certSign/useCertSignParameters";
@@ -19,7 +20,7 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
         <Stack gap="sm">
           <FileUploadButton
             file={parameters.privateKeyFile}
-            onChange={(file) => onParameterChange('privateKeyFile', file || undefined)}
+            onChange={(file) => onParameterChange('privateKeyFile', file ?? undefined)}
             accept=".pem,.der,.key"
             disabled={disabled}
             placeholder={t('certSign.choosePrivateKey', 'Choose Private Key File')}
@@ -27,7 +28,7 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
           {parameters.privateKeyFile && (
             <FileUploadButton
               file={parameters.certFile}
-              onChange={(file) => onParameterChange('certFile', file || undefined)}
+              onChange={(file) => onParameterChange('certFile', file ?? undefined)}
               accept=".pem,.der,.crt,.cer"
               disabled={disabled}
               placeholder={t('certSign.chooseCertificate', 'Choose Certificate File')}
@@ -39,7 +40,7 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
       {parameters.certType === 'PKCS12' && (
         <FileUploadButton
           file={parameters.p12File}
-          onChange={(file) => onParameterChange('p12File', file || undefined)}
+          onChange={(file) => onParameterChange('p12File', file ?? undefined)}
           accept=".p12"
           disabled={disabled}
           placeholder={t('certSign.chooseP12File', 'Choose PKCS12 File')}
@@ -49,7 +50,7 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
       {parameters.certType === 'PFX' && (
         <FileUploadButton
           file={parameters.p12File}
-          onChange={(file) => onParameterChange('p12File', file || undefined)}
+          onChange={(file) => onParameterChange('p12File', file ?? undefined)}
           accept=".pfx"
           disabled={disabled}
           placeholder={t('certSign.choosePfxFile', 'Choose PFX File')}
@@ -59,7 +60,7 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
       {parameters.certType === 'JKS' && (
         <FileUploadButton
           file={parameters.jksFile}
-          onChange={(file) => onParameterChange('jksFile', file || undefined)}
+          onChange={(file) => onParameterChange('jksFile', file ?? undefined)}
           accept=".jks,.keystore"
           disabled={disabled}
           placeholder={t('certSign.chooseJksFile', 'Choose JKS File')}
@@ -74,9 +75,9 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
 
       {/* Password - only show when files are uploaded */}
       {parameters.certType && (
-        (parameters.certType === 'PEM' && parameters.privateKeyFile && parameters.certFile) ||
-        (parameters.certType === 'PKCS12' && parameters.p12File) ||
-        (parameters.certType === 'PFX' && parameters.p12File) ||
+        (parameters.certType === 'PEM' && parameters.privateKeyFile && parameters.certFile) ??
+        (parameters.certType === 'PKCS12' && parameters.p12File) ??
+        (parameters.certType === 'PFX' && parameters.p12File) ??
         (parameters.certType === 'JKS' && parameters.jksFile)
       ) && (
         <TextInput
@@ -92,4 +93,4 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
   );
 };
 
-export default CertificateFilesSettings;
\ No newline at end of file
+export default CertificateFilesSettings;
diff --git a/frontend/src/components/tools/certSign/CertificateFormatSettings.tsx b/frontend/src/components/tools/certSign/CertificateFormatSettings.tsx
index 6fac53f4d..54498a5b2 100644
--- a/frontend/src/components/tools/certSign/CertificateFormatSettings.tsx
+++ b/frontend/src/components/tools/certSign/CertificateFormatSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Button } from "@mantine/core";
 import { CertSignParameters } from "../../../hooks/tools/certSign/useCertSignParameters";
 
diff --git a/frontend/src/components/tools/certSign/CertificateTypeSettings.tsx b/frontend/src/components/tools/certSign/CertificateTypeSettings.tsx
index 2d514a161..acc216014 100644
--- a/frontend/src/components/tools/certSign/CertificateTypeSettings.tsx
+++ b/frontend/src/components/tools/certSign/CertificateTypeSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Button } from "@mantine/core";
 import { CertSignParameters } from "../../../hooks/tools/certSign/useCertSignParameters";
 import { useAppConfig } from "../../../hooks/useAppConfig";
diff --git a/frontend/src/components/tools/certSign/SignatureAppearanceSettings.tsx b/frontend/src/components/tools/certSign/SignatureAppearanceSettings.tsx
index aa99be742..5e382d5f7 100644
--- a/frontend/src/components/tools/certSign/SignatureAppearanceSettings.tsx
+++ b/frontend/src/components/tools/certSign/SignatureAppearanceSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Text, Button, TextInput, NumberInput } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { CertSignParameters } from "../../../hooks/tools/certSign/useCertSignParameters";
diff --git a/frontend/src/components/tools/changeMetadata/ChangeMetadataSingleStep.tsx b/frontend/src/components/tools/changeMetadata/ChangeMetadataSingleStep.tsx
index ef95718e9..3304c2269 100644
--- a/frontend/src/components/tools/changeMetadata/ChangeMetadataSingleStep.tsx
+++ b/frontend/src/components/tools/changeMetadata/ChangeMetadataSingleStep.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Divider, Text } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { ChangeMetadataParameters, createCustomMetadataFunctions } from "../../../hooks/tools/changeMetadata/useChangeMetadataParameters";
diff --git a/frontend/src/components/tools/changeMetadata/steps/AdvancedOptionsStep.tsx b/frontend/src/components/tools/changeMetadata/steps/AdvancedOptionsStep.tsx
index 0edffe21d..27eade4c7 100644
--- a/frontend/src/components/tools/changeMetadata/steps/AdvancedOptionsStep.tsx
+++ b/frontend/src/components/tools/changeMetadata/steps/AdvancedOptionsStep.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Select, Divider } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { ChangeMetadataParameters } from "../../../../hooks/tools/changeMetadata/useChangeMetadataParameters";
diff --git a/frontend/src/components/tools/changeMetadata/steps/CustomMetadataStep.tsx b/frontend/src/components/tools/changeMetadata/steps/CustomMetadataStep.tsx
index beb139e50..6b1385ec2 100644
--- a/frontend/src/components/tools/changeMetadata/steps/CustomMetadataStep.tsx
+++ b/frontend/src/components/tools/changeMetadata/steps/CustomMetadataStep.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, TextInput, Button, Group, Text } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { ChangeMetadataParameters } from "../../../../hooks/tools/changeMetadata/useChangeMetadataParameters";
diff --git a/frontend/src/components/tools/changeMetadata/steps/DeleteAllStep.tsx b/frontend/src/components/tools/changeMetadata/steps/DeleteAllStep.tsx
index fbd983a18..d97b0c9dd 100644
--- a/frontend/src/components/tools/changeMetadata/steps/DeleteAllStep.tsx
+++ b/frontend/src/components/tools/changeMetadata/steps/DeleteAllStep.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Checkbox } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { ChangeMetadataParameters } from "../../../../hooks/tools/changeMetadata/useChangeMetadataParameters";
diff --git a/frontend/src/components/tools/changeMetadata/steps/DocumentDatesStep.tsx b/frontend/src/components/tools/changeMetadata/steps/DocumentDatesStep.tsx
index e46e7799d..949f54491 100644
--- a/frontend/src/components/tools/changeMetadata/steps/DocumentDatesStep.tsx
+++ b/frontend/src/components/tools/changeMetadata/steps/DocumentDatesStep.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack } from "@mantine/core";
 import { DateTimePicker } from "@mantine/dates";
 import { useTranslation } from "react-i18next";
diff --git a/frontend/src/components/tools/changeMetadata/steps/StandardMetadataStep.tsx b/frontend/src/components/tools/changeMetadata/steps/StandardMetadataStep.tsx
index 02b5715cd..741bb63a1 100644
--- a/frontend/src/components/tools/changeMetadata/steps/StandardMetadataStep.tsx
+++ b/frontend/src/components/tools/changeMetadata/steps/StandardMetadataStep.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, TextInput } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { ChangeMetadataParameters } from "../../../../hooks/tools/changeMetadata/useChangeMetadataParameters";
diff --git a/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.test.tsx b/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.test.tsx
index 14d0cf1e4..a70f67481 100644
--- a/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.test.tsx
+++ b/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.test.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { describe, expect, test, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/react';
 import { MantineProvider } from '@mantine/core';
diff --git a/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.tsx b/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.tsx
index 83e132ec6..f6d365e44 100644
--- a/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.tsx
+++ b/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Checkbox } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { ChangePermissionsParameters } from "../../../hooks/tools/changePermissions/useChangePermissionsParameters";
diff --git a/frontend/src/components/tools/convert/ConvertToPdfaSettings.tsx b/frontend/src/components/tools/convert/ConvertToPdfaSettings.tsx
index b9a572b8d..e1ca71b74 100644
--- a/frontend/src/components/tools/convert/ConvertToPdfaSettings.tsx
+++ b/frontend/src/components/tools/convert/ConvertToPdfaSettings.tsx
@@ -44,7 +44,7 @@ const ConvertToPdfaSettings = ({
           value={parameters.pdfaOptions.outputFormat}
           onChange={(value) => onParameterChange('pdfaOptions', {
             ...parameters.pdfaOptions,
-            outputFormat: value || 'pdfa-1'
+            outputFormat: value ?? 'pdfa-1'
           })}
           data={pdfaFormatOptions}
           disabled={disabled || isChecking}
diff --git a/frontend/src/components/tools/crop/CropSettings.tsx b/frontend/src/components/tools/crop/CropSettings.tsx
index dafcdeaab..9301bb25a 100644
--- a/frontend/src/components/tools/crop/CropSettings.tsx
+++ b/frontend/src/components/tools/crop/CropSettings.tsx
@@ -1,4 +1,4 @@
-import { useMemo, useState, useEffect } from "react";
+import React, { useMemo, useState, useEffect } from "react";
 import { Stack, Text, Box, Group, NumberInput, ActionIcon, Center, Alert } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import RestartAltIcon from "@mui/icons-material/RestartAlt";
@@ -48,7 +48,7 @@ const CropSettings = ({ parameters, disabled = false }: CropSettingsProps) => {
         return;
       }
 
-      setThumbnail(selectedStub.thumbnailUrl || null);
+      setThumbnail(selectedStub.thumbnailUrl ?? null);
 
       try {
         // Get PDF dimensions from the actual file
@@ -89,7 +89,7 @@ const CropSettings = ({ parameters, disabled = false }: CropSettingsProps) => {
       }
     };
 
-    loadPDFDimensions();
+    void loadPDFDimensions();
   }, [selectedStub, selectedFile, parameters]);
 
   // Current crop area
diff --git a/frontend/src/components/tools/flatten/FlattenSettings.tsx b/frontend/src/components/tools/flatten/FlattenSettings.tsx
index 8386ad493..7c85ec401 100644
--- a/frontend/src/components/tools/flatten/FlattenSettings.tsx
+++ b/frontend/src/components/tools/flatten/FlattenSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Text, Checkbox } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { FlattenParameters } from "../../../hooks/tools/flatten/useFlattenParameters";
diff --git a/frontend/src/components/tools/merge/MergeFileSorter.test.tsx b/frontend/src/components/tools/merge/MergeFileSorter.test.tsx
index 302777261..b19e1f4f9 100644
--- a/frontend/src/components/tools/merge/MergeFileSorter.test.tsx
+++ b/frontend/src/components/tools/merge/MergeFileSorter.test.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { describe, expect, test, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/react';
 import { MantineProvider } from '@mantine/core';
diff --git a/frontend/src/components/tools/merge/MergeSettings.test.tsx b/frontend/src/components/tools/merge/MergeSettings.test.tsx
index 7989fa6d0..657d3199a 100644
--- a/frontend/src/components/tools/merge/MergeSettings.test.tsx
+++ b/frontend/src/components/tools/merge/MergeSettings.test.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { describe, expect, test, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/react';
 import { MantineProvider } from '@mantine/core';
diff --git a/frontend/src/components/tools/ocr/LanguagePicker.tsx b/frontend/src/components/tools/ocr/LanguagePicker.tsx
index 31f0fe301..d94a34613 100644
--- a/frontend/src/components/tools/ocr/LanguagePicker.tsx
+++ b/frontend/src/components/tools/ocr/LanguagePicker.tsx
@@ -75,7 +75,7 @@ const LanguagePicker: React.FC<LanguagePickerProps> = ({
       }
     };
 
-    fetchLanguages();
+    void fetchLanguages();
   }, [languagesEndpoint]);
 
   // Auto-fill OCR language based on browser language when languages are loaded
diff --git a/frontend/src/components/tools/ocr/OCRSettings.tsx b/frontend/src/components/tools/ocr/OCRSettings.tsx
index 959601166..9aff013c3 100644
--- a/frontend/src/components/tools/ocr/OCRSettings.tsx
+++ b/frontend/src/components/tools/ocr/OCRSettings.tsx
@@ -23,7 +23,7 @@ const OCRSettings: React.FC<OCRSettingsProps> = ({
       <Select
         label={t('ocr.settings.ocrMode.label', 'OCR Mode')}
         value={parameters.ocrType}
-        onChange={(value) => onParameterChange('ocrType', value || 'skip-text')}
+        onChange={(value) => onParameterChange('ocrType', value ?? 'skip-text')}
         data={[
           { value: 'skip-text', label: t('ocr.settings.ocrMode.auto', 'Auto (skip text layers)') },
           { value: 'force-ocr', label: t('ocr.settings.ocrMode.force', 'Force (re-OCR all, replace text)') },
diff --git a/frontend/src/components/tools/redact/RedactAdvancedSettings.test.tsx b/frontend/src/components/tools/redact/RedactAdvancedSettings.test.tsx
index 92f359abd..8d314daa5 100644
--- a/frontend/src/components/tools/redact/RedactAdvancedSettings.test.tsx
+++ b/frontend/src/components/tools/redact/RedactAdvancedSettings.test.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { describe, expect, test, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/react';
 import { MantineProvider } from '@mantine/core';
diff --git a/frontend/src/components/tools/redact/RedactAdvancedSettings.tsx b/frontend/src/components/tools/redact/RedactAdvancedSettings.tsx
index 26a96056b..4df502b4d 100644
--- a/frontend/src/components/tools/redact/RedactAdvancedSettings.tsx
+++ b/frontend/src/components/tools/redact/RedactAdvancedSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, NumberInput, ColorInput, Checkbox } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { RedactParameters } from "../../../hooks/tools/redact/useRedactParameters";
diff --git a/frontend/src/components/tools/redact/RedactModeSelector.tsx b/frontend/src/components/tools/redact/RedactModeSelector.tsx
index c073bc520..13acb700a 100644
--- a/frontend/src/components/tools/redact/RedactModeSelector.tsx
+++ b/frontend/src/components/tools/redact/RedactModeSelector.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { useTranslation } from 'react-i18next';
 import { RedactMode } from '../../../hooks/tools/redact/useRedactParameters';
 import ButtonSelector from '../../shared/ButtonSelector';
diff --git a/frontend/src/components/tools/redact/RedactSingleStepSettings.test.tsx b/frontend/src/components/tools/redact/RedactSingleStepSettings.test.tsx
index 2bfe94e06..928454c0a 100644
--- a/frontend/src/components/tools/redact/RedactSingleStepSettings.test.tsx
+++ b/frontend/src/components/tools/redact/RedactSingleStepSettings.test.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { describe, expect, test, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/react';
 import { MantineProvider } from '@mantine/core';
diff --git a/frontend/src/components/viewer/SearchInterface.tsx b/frontend/src/components/viewer/SearchInterface.tsx
index 71b8f17b9..588084317 100644
--- a/frontend/src/components/viewer/SearchInterface.tsx
+++ b/frontend/src/components/viewer/SearchInterface.tsx
@@ -80,7 +80,7 @@ export function SearchInterface({ visible, onClose }: SearchInterfaceProps) {
 
   const handleKeyDown = (event: React.KeyboardEvent<HTMLInputElement>) => {
     if (event.key === 'Enter') {
-      handleSearch(searchQuery);
+      void handleSearch(searchQuery);
     } else if (event.key === 'Escape') {
       onClose();
     }
diff --git a/frontend/src/components/viewer/ThumbnailSidebar.tsx b/frontend/src/components/viewer/ThumbnailSidebar.tsx
index 5abb472bf..b3848ba02 100644
--- a/frontend/src/components/viewer/ThumbnailSidebar.tsx
+++ b/frontend/src/components/viewer/ThumbnailSidebar.tsx
@@ -65,7 +65,7 @@ export function ThumbnailSidebar({ visible, onToggle: _onToggle }: ThumbnailSide
       }
     };
 
-    generateThumbnails();
+    void generateThumbnails();
   }, [visible, scrollState.totalPages, thumbnailAPI]);
 
   const handlePageClick = (pageIndex: number) => {
diff --git a/frontend/src/contexts/FilesModalContext.tsx b/frontend/src/contexts/FilesModalContext.tsx
index e850fa4dd..da141eebd 100644
--- a/frontend/src/contexts/FilesModalContext.tsx
+++ b/frontend/src/contexts/FilesModalContext.tsx
@@ -43,7 +43,7 @@ export const FilesModalProvider: React.FC<{ children: React.ReactNode }> = ({ ch
       customHandler(files, insertAfterPage);
     } else {
       // Use normal file handling
-      addFiles(files);
+      void addFiles(files);
     }
     closeFilesModal();
   }, [addFiles, closeFilesModal, insertAfterPage, customHandler]);
@@ -59,7 +59,7 @@ export const FilesModalProvider: React.FC<{ children: React.ReactNode }> = ({ ch
             loadedFiles.push(stirlingFile);
           }
         }
-        
+
         if (loadedFiles.length > 0) {
           customHandler(loadedFiles, insertAfterPage);
         }
@@ -69,7 +69,11 @@ export const FilesModalProvider: React.FC<{ children: React.ReactNode }> = ({ ch
     } else {
       // Normal case - use addStirlingFileStubs to preserve metadata
       if (actions.addStirlingFileStubs) {
-        actions.addStirlingFileStubs(stirlingFileStubs, { selectFiles: true });
+        try {
+          await actions.addStirlingFileStubs(stirlingFileStubs, { selectFiles: true });
+        } catch (error) {
+          console.error('Error adding Stirling file stubs:', error);
+        }
       } else {
         console.error('addStirlingFileStubs action not available');
       }
diff --git a/frontend/src/hooks/tools/automate/useSavedAutomations.ts b/frontend/src/hooks/tools/automate/useSavedAutomations.ts
index 8ad7a80b6..86eceacc8 100644
--- a/frontend/src/hooks/tools/automate/useSavedAutomations.ts
+++ b/frontend/src/hooks/tools/automate/useSavedAutomations.ts
@@ -26,7 +26,7 @@ export function useSavedAutomations() {
   }, []);
 
   const refreshAutomations = useCallback(() => {
-    loadSavedAutomations();
+    void loadSavedAutomations();
   }, [loadSavedAutomations]);
 
   const deleteAutomation = useCallback(async (id: string) => {
@@ -80,7 +80,7 @@ export function useSavedAutomations() {
 
   // Load automations on mount
   useEffect(() => {
-    loadSavedAutomations();
+    void loadSavedAutomations();
   }, [loadSavedAutomations]);
 
   return {
diff --git a/frontend/src/hooks/tools/changeMetadata/useMetadataExtraction.ts b/frontend/src/hooks/tools/changeMetadata/useMetadataExtraction.ts
index 423e19d7e..370b1805f 100644
--- a/frontend/src/hooks/tools/changeMetadata/useMetadataExtraction.ts
+++ b/frontend/src/hooks/tools/changeMetadata/useMetadataExtraction.ts
@@ -60,7 +60,7 @@ export const useMetadataExtraction = (params: MetadataExtractionParams) => {
       setIsExtractingMetadata(false);
     };
 
-    extractMetadata();
+    void extractMetadata();
   }, [selectedFiles, hasExtractedMetadata, params]);
 
   return {
diff --git a/frontend/src/hooks/useAppConfig.ts b/frontend/src/hooks/useAppConfig.ts
index cb23cfb60..20fb7d2fd 100644
--- a/frontend/src/hooks/useAppConfig.ts
+++ b/frontend/src/hooks/useAppConfig.ts
@@ -65,7 +65,7 @@ export function useAppConfig(): UseAppConfigReturn {
   };
 
   useEffect(() => {
-    fetchConfig();
+    void fetchConfig();
   }, []);
 
   return {
diff --git a/frontend/src/hooks/useEndpointConfig.ts b/frontend/src/hooks/useEndpointConfig.ts
index 7516826ed..de87cb33f 100644
--- a/frontend/src/hooks/useEndpointConfig.ts
+++ b/frontend/src/hooks/useEndpointConfig.ts
@@ -41,7 +41,7 @@ export function useEndpointEnabled(endpoint: string): {
   };
 
   useEffect(() => {
-    fetchEndpointStatus();
+    void fetchEndpointStatus();
   }, [endpoint]);
 
   return {
@@ -105,7 +105,7 @@ export function useMultipleEndpointsEnabled(endpoints: string[]): {
   };
 
   useEffect(() => {
-    fetchAllEndpointStatuses();
+    void fetchAllEndpointStatuses();
   }, [endpoints.join(',')]); // Re-run when endpoints array changes
 
   return {
diff --git a/frontend/src/hooks/useEnhancedProcessedFiles.ts b/frontend/src/hooks/useEnhancedProcessedFiles.ts
index b29107734..8bd38e959 100644
--- a/frontend/src/hooks/useEnhancedProcessedFiles.ts
+++ b/frontend/src/hooks/useEnhancedProcessedFiles.ts
@@ -104,7 +104,7 @@ export function useEnhancedProcessedFiles(
       }
     };
 
-    processFiles();
+    void processFiles();
   }, [activeFiles]); // Only depend on activeFiles to avoid infinite loops
 
   // Listen for processing completion
diff --git a/frontend/src/hooks/useIndexedDBThumbnail.ts b/frontend/src/hooks/useIndexedDBThumbnail.ts
index 389ef5f49..8edfa0153 100644
--- a/frontend/src/hooks/useIndexedDBThumbnail.ts
+++ b/frontend/src/hooks/useIndexedDBThumbnail.ts
@@ -2,7 +2,6 @@ import { useState, useEffect } from "react";
 import { StirlingFileStub } from "../types/fileContext";
 import { useIndexedDB } from "../contexts/IndexedDBContext";
 import { generateThumbnailForFile } from "../utils/thumbnailUtils";
-import { FileId } from "../types/fileContext";
 
 
 /**
@@ -75,7 +74,7 @@ export function useIndexedDBThumbnail(file: StirlingFileStub | undefined | null)
       }
     }
 
-    loadThumbnail();
+    void loadThumbnail();
     return () => { cancelled = true; };
   }, [file, file?.thumbnailUrl, file?.id, indexedDB, generating]);
 
diff --git a/frontend/src/hooks/usePdfSignatureDetection.ts b/frontend/src/hooks/usePdfSignatureDetection.ts
index 77b7f79ac..552c1ab3c 100644
--- a/frontend/src/hooks/usePdfSignatureDetection.ts
+++ b/frontend/src/hooks/usePdfSignatureDetection.ts
@@ -58,7 +58,7 @@ export const usePdfSignatureDetection = (files: StirlingFile[]): PdfSignatureDet
       setIsChecking(false);
     };
 
-    checkForDigitalSignatures();
+    void checkForDigitalSignatures();
   }, [files]);
 
   return {
diff --git a/frontend/src/hooks/useProcessedFiles.ts b/frontend/src/hooks/useProcessedFiles.ts
index 7ee36ab9e..00fc066ec 100644
--- a/frontend/src/hooks/useProcessedFiles.ts
+++ b/frontend/src/hooks/useProcessedFiles.ts
@@ -36,7 +36,7 @@ export function useProcessedFiles(activeFiles: File[]): UseProcessedFilesResult
       setProcessedFiles(newProcessedFiles);
     };
 
-    checkProcessing();
+    void checkProcessing();
 
     return unsubscribe;
   }, [activeFiles]);
diff --git a/frontend/src/i18n.ts b/frontend/src/i18n.ts
index f57d4b1e3..d35468d84 100644
--- a/frontend/src/i18n.ts
+++ b/frontend/src/i18n.ts
@@ -52,7 +52,7 @@ export const supportedLanguages = {
 // RTL languages (based on your existing language.direction property)
 export const rtlLanguages = ['ar-AR', 'fa-IR'];
 
-i18n
+void i18n
   .use(Backend)
   .use(LanguageDetector)
   .use(initReactI18next)
diff --git a/frontend/src/i18n/config.ts b/frontend/src/i18n/config.ts
index 2a7e6a431..467196bc6 100644
--- a/frontend/src/i18n/config.ts
+++ b/frontend/src/i18n/config.ts
@@ -2,7 +2,7 @@ import i18n from 'i18next';
 import { initReactI18next } from 'react-i18next';
 import Backend from 'i18next-http-backend';
 
-i18n
+void i18n
   .use(Backend)
   .use(initReactI18next)
   .init({
@@ -29,7 +29,7 @@ i18n
           'convert.singleOrMultiple': 'Output',
           'convert.emailNote': 'Email attachments and embedded images will be included',
           'common.color': 'Color',
-          'common.grayscale': 'Grayscale', 
+          'common.grayscale': 'Grayscale',
           'common.blackWhite': 'Black & White',
           'common.single': 'Single Image',
           'common.multiple': 'Multiple Images',
@@ -45,4 +45,4 @@ i18n
     }
   });
 
-export default i18n;
\ No newline at end of file
+export default i18n;
diff --git a/frontend/src/services/enhancedPDFProcessingService.ts b/frontend/src/services/enhancedPDFProcessingService.ts
index 3795ef78c..ee04a1db3 100644
--- a/frontend/src/services/enhancedPDFProcessingService.ts
+++ b/frontend/src/services/enhancedPDFProcessingService.ts
@@ -70,7 +70,7 @@ export class EnhancedPDFProcessingService {
     };
 
     // Start processing
-    this.startProcessing(file, fileKey, config, analysis.estimatedProcessingTime);
+    await this.startProcessing(file, fileKey, config, analysis.estimatedProcessingTime);
     return null;
   }
 
diff --git a/frontend/src/services/fileProcessingService.ts b/frontend/src/services/fileProcessingService.ts
index 6bd3011e9..4e7206dc8 100644
--- a/frontend/src/services/fileProcessingService.ts
+++ b/frontend/src/services/fileProcessingService.ts
@@ -60,7 +60,7 @@ class FileProcessingService {
     this.processingCache.set(fileId, operation);
 
     // Clean up cache after completion
-    processingPromise.finally(() => {
+    void processingPromise.finally(() => {
       this.processingCache.delete(fileId);
     });
 
diff --git a/frontend/src/services/fileStorage.ts b/frontend/src/services/fileStorage.ts
index 57a611173..13ef040df 100644
--- a/frontend/src/services/fileStorage.ts
+++ b/frontend/src/services/fileStorage.ts
@@ -78,7 +78,7 @@ class FileStorageService {
 
         request.onerror = () => {
           console.error('IndexedDB add error:', request.error);
-          reject(new Error(request.error?.message || 'Unknown error occurred'));
+          reject(new Error(request.error?.message ?? 'Unknown error occurred'));
         };
         request.onsuccess = () => {
           resolve();
@@ -101,7 +101,7 @@ class FileStorageService {
       const store = transaction.objectStore(this.storeName);
       const request = store.get(id);
 
-      request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+      request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       request.onsuccess = () => {
         const record = request.result as StoredStirlingFileRecord | undefined;
         if (!record) {
@@ -142,7 +142,7 @@ class FileStorageService {
       const store = transaction.objectStore(this.storeName);
       const request = store.get(id);
 
-      request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+      request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       request.onsuccess = () => {
         const record = request.result as StoredStirlingFileRecord | undefined;
         if (!record) {
@@ -184,7 +184,7 @@ class FileStorageService {
       const request = store.openCursor();
       const stubs: StirlingFileStub[] = [];
 
-      request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+      request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       request.onsuccess = (event) => {
         const cursor = (event.target as IDBRequest).result;
         if (cursor) {
@@ -227,7 +227,7 @@ class FileStorageService {
       const request = store.openCursor();
       const leafStubs: StirlingFileStub[] = [];
 
-      request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+      request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       request.onsuccess = (event) => {
         const cursor = (event.target as IDBRequest).result;
         if (cursor) {
@@ -269,7 +269,7 @@ class FileStorageService {
       const store = transaction.objectStore(this.storeName);
       const request = store.delete(id);
 
-      request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+      request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       request.onsuccess = () => resolve();
     });
   }
@@ -326,7 +326,7 @@ class FileStorageService {
       const store = transaction.objectStore(this.storeName);
       const request = store.clear();
 
-      request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+      request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       request.onsuccess = () => resolve();
     });
   }
@@ -384,7 +384,7 @@ class FileStorageService {
         const store = transaction.objectStore(this.storeName);
         const request = store.get(id);
 
-        request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+        request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
         request.onsuccess = () => {
           const record = request.result as StoredStirlingFileRecord | undefined;
           if (record) {
@@ -415,7 +415,7 @@ class FileStorageService {
       const record = await new Promise<StoredStirlingFileRecord | undefined>((resolve, reject) => {
         const request = store.get(fileId);
         request.onsuccess = () => resolve(request.result);
-        request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+        request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       });
 
       if (!record) {
@@ -428,7 +428,7 @@ class FileStorageService {
       await new Promise<void>((resolve, reject) => {
         const request = store.put(record);
         request.onsuccess = () => resolve();
-        request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+        request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       });
 
       return true;
@@ -451,7 +451,7 @@ class FileStorageService {
       const record = await new Promise<StoredStirlingFileRecord | undefined>((resolve, reject) => {
         const request = store.get(fileId);
         request.onsuccess = () => resolve(request.result);
-        request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+        request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       });
 
       if (!record) {
@@ -464,7 +464,7 @@ class FileStorageService {
       await new Promise<void>((resolve, reject) => {
         const request = store.put(record);
         request.onsuccess = () => resolve();
-        request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+        request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       });
 
       return true;
diff --git a/frontend/src/services/indexedDBManager.ts b/frontend/src/services/indexedDBManager.ts
index 7bf55905f..17415fdc3 100644
--- a/frontend/src/services/indexedDBManager.ts
+++ b/frontend/src/services/indexedDBManager.ts
@@ -67,7 +67,7 @@ class IndexedDBManager {
 
       request.onerror = () => {
         console.error(`Failed to open ${config.name}:`, request.error);
-        reject(new Error(request.error?.message || 'Unknown error occurred while opening the database'));
+        reject(new Error(request.error?.message ?? 'Unknown error occurred while opening the database'));
       };
 
       request.onsuccess = () => {
@@ -257,7 +257,7 @@ class IndexedDBManager {
     return new Promise((resolve, reject) => {
       const deleteRequest = indexedDB.deleteDatabase(name);
 
-      deleteRequest.onerror = () => reject(new Error(deleteRequest.error?.message || 'Unknown error occurred while deleting the database'));
+      deleteRequest.onerror = () => reject(new Error(deleteRequest.error?.message ?? 'Unknown error occurred while deleting the database'));
       deleteRequest.onsuccess = () => {
         console.log(`Deleted database: ${name}`);
         resolve();
diff --git a/frontend/src/services/pdfProcessingService.ts b/frontend/src/services/pdfProcessingService.ts
index abcd492ac..9abf46142 100644
--- a/frontend/src/services/pdfProcessingService.ts
+++ b/frontend/src/services/pdfProcessingService.ts
@@ -35,7 +35,7 @@ export class PDFProcessingService {
     }
 
     // Start processing
-    this.startProcessing(file, fileKey);
+    void this.startProcessing(file, fileKey);
     return null;
   }
 
diff --git a/frontend/src/services/pdfWorkerManager.ts b/frontend/src/services/pdfWorkerManager.ts
index 13f18d023..db82f6d29 100644
--- a/frontend/src/services/pdfWorkerManager.ts
+++ b/frontend/src/services/pdfWorkerManager.ts
@@ -94,7 +94,7 @@ class PDFWorkerManager {
       // If document creation fails, make sure to clean up the loading task
       if (loadingTask) {
         try {
-          loadingTask.destroy();
+          await loadingTask.destroy();
         } catch {
           // Ignore errors
         }
@@ -109,7 +109,7 @@ class PDFWorkerManager {
   destroyDocument(pdf: PDFDocumentProxy): void {
     if (this.activeDocuments.has(pdf)) {
       try {
-        pdf.destroy();
+        void pdf.destroy();
         this.activeDocuments.delete(pdf);
         this.workerCount = Math.max(0, this.workerCount - 1);
       } catch {
@@ -167,7 +167,7 @@ class PDFWorkerManager {
     // Force destroy all documents
     this.activeDocuments.forEach(pdf => {
       try {
-        pdf.destroy();
+        void pdf.destroy();
       } catch {
         // Ignore errors
       }
diff --git a/frontend/src/tools/AdjustPageScale.tsx b/frontend/src/tools/AdjustPageScale.tsx
index 26159f551..3a00e0002 100644
--- a/frontend/src/tools/AdjustPageScale.tsx
+++ b/frontend/src/tools/AdjustPageScale.tsx
@@ -52,7 +52,7 @@ const AdjustPageScale = (props: BaseToolProps) => {
       title: t("adjustPageScale.title", "Page Scale Results"),
       onFileClick: base.handleThumbnailClick,
       onUndo: () => {
-        base.handleUndo();
+        void base.handleUndo();
       },
     },
   });
diff --git a/frontend/src/tools/Crop.tsx b/frontend/src/tools/Crop.tsx
index d185e3877..dd398619c 100644
--- a/frontend/src/tools/Crop.tsx
+++ b/frontend/src/tools/Crop.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { useTranslation } from "react-i18next";
 import { createToolFlow } from "../components/tools/shared/createToolFlow";
 import CropSettings from "../components/tools/crop/CropSettings";
diff --git a/frontend/src/tools/RemovePassword.tsx b/frontend/src/tools/RemovePassword.tsx
index 970eb324b..f7afe9973 100644
--- a/frontend/src/tools/RemovePassword.tsx
+++ b/frontend/src/tools/RemovePassword.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { useTranslation } from "react-i18next";
 import { createToolFlow } from "../components/tools/shared/createToolFlow";
 import RemovePasswordSettings from "../components/tools/removePassword/RemovePasswordSettings";
diff --git a/frontend/src/tools/Rotate.tsx b/frontend/src/tools/Rotate.tsx
index 0b45d8d54..40b75f69a 100644
--- a/frontend/src/tools/Rotate.tsx
+++ b/frontend/src/tools/Rotate.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { useTranslation } from "react-i18next";
 import { createToolFlow } from "../components/tools/shared/createToolFlow";
 import RotateSettings from "../components/tools/rotate/RotateSettings";