feat:(pdfa-conversion) Implement Strict PDF/A Mode with Verification (#5663)

# Description of Changes


This PR introduces a new "Strict Mode" for the PDF to PDF/A conversion
tool. When enabled, the application will use VeraPDF to verify that the
resulting file is perfectly compliant with the selected PDF/A standard.
If validation fails, the system will return a descriptive error instead
of a non-compliant file.



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- Any challenges encountered

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---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### Translations (if applicable)

- [ ] I ran
[`scripts/counter_translation.py`](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/docs/counter_translation.md)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

---------

Signed-off-by: Balázs Szücs <[email protected]>

frontend/src/core/components/tools/convert/ConvertSettings.tsx

@@ -146,7 +146,8 @@ const ConvertSettings = ({
       includeAllRecipients: false,
     });
     onParameterChange('pdfaOptions', {
-      outputFormat: 'pdfa-1',
+      outputFormat: 'pdfa-2b',
+      strict: false,
     });
     onParameterChange('pdfxOptions', {
       outputFormat: 'pdfx',
@@ -234,7 +235,8 @@ const ConvertSettings = ({
       includeAllRecipients: false,
     });
     onParameterChange('pdfaOptions', {
-      outputFormat: 'pdfa-1',
+      outputFormat: 'pdfa-2b',
+      strict: false,
     });
     onParameterChange('pdfxOptions', {
       outputFormat: 'pdfx',

frontend/src/core/components/tools/convert/ConvertToPdfaSettings.tsx

@@ -1,4 +1,4 @@
-import { Stack, Text, Select, Alert } from '@mantine/core';
+import { Stack, Text, Select, Alert, Checkbox } from '@mantine/core';
 import { useTranslation } from 'react-i18next';
 import { ConvertParameters } from '@app/hooks/tools/convert/useConvertParameters';
 import { usePdfSignatureDetection } from '@app/hooks/usePdfSignatureDetection';
@@ -23,8 +23,8 @@ const ConvertToPdfaSettings = ({
 
   const pdfaFormatOptions = [
     { value: 'pdfa-1', label: 'PDF/A-1b' },
-    { value: 'pdfa', label: 'PDF/A-2b' },
-    { value: 'pdfa-3', label: 'PDF/A-3b' }
+    { value: 'pdfa-2b', label: 'PDF/A-2b' },
+    { value: 'pdfa-3b', label: 'PDF/A-3b' }
   ];
 
   return (
@@ -45,7 +45,7 @@ const ConvertToPdfaSettings = ({
           value={parameters.pdfaOptions.outputFormat}
           onChange={(value) => onParameterChange('pdfaOptions', {
             ...parameters.pdfaOptions,
-            outputFormat: value || 'pdfa-1'
+            outputFormat: value || 'pdfa-2b'
           })}
           data={pdfaFormatOptions}
           disabled={disabled || isChecking}
@@ -56,6 +56,17 @@ const ConvertToPdfaSettings = ({
           {t("convert.pdfaNote", "PDF/A-1b is more compatible, PDF/A-2b supports more features, PDF/A-3b supports embedded files.")}
         </Text>
       </Stack>
+
+      <Checkbox
+        label={t("convert.strictMode", "Strict Mode")}
+        description={t("convert.strictModeDesc", "Error if conversion is not perfect (uses VeraPDF verification)")}
+        checked={parameters.pdfaOptions.strict}
+        onChange={(event) => onParameterChange('pdfaOptions', {
+          ...parameters.pdfaOptions,
+          strict: event.currentTarget.checked
+        })}
+        disabled={disabled || isChecking}
+      />
     </Stack>
   );
 };