Improve Type Safety and OpenAPI Schema for PDF API Controllers and Models (#3470)

# Description of Changes

- **What was changed**  
- Updated controller methods to use strongly‐typed primitives (`int`,
`long`, `boolean`) instead of `String` for numeric and boolean
parameters, eliminating calls to `Integer.parseInt`/`Long.parseLong` and
improving null‐safety (`Boolean.TRUE.equals(...)`).
- Enhanced all API request model classes with richer Swagger/OpenAPI
annotations: added `requiredMode`, `defaultValue`, `allowableValues`,
`format`, `pattern`, and tightened schema descriptions for all fields.
- Refactored HTML form templates for “Remove Blank Pages” to include
`min`, `max`, and `step` attributes on numeric inputs, matching the
updated validation rules.

- **Why the change was made**  
- **Type safety & robustness**: Shifting from `String` to native types
prevents runtime parsing errors, simplifies controller logic, and makes
default values explicit.
- **Better API documentation & validation**: Enriching the Swagger
annotations ensures generated docs accurately reflect required fields,
default values, and permitted ranges, which improves client code
generation and developer experience.
- **Consistency across codebase**: Aligning all request models and
controllers enforces a uniform coding style and reduces bugs.

#3406

---

## Checklist

### General

- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/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/HowToAddNewLanguage.md)
(if applicable)
- [x] I have performed a self-review of my own code
- [x] 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/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### 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/DeveloperGuide.md#6-testing)
for more details.

src/main/java/stirling/software/SPDF/controller/api/AnalysisController.java

@@ -59,7 +59,8 @@ public class AnalysisController {
             description = "Returns title, author, subject, etc. Input:PDF Output:JSON Type:SISO")
     public Map<String, String> getDocumentProperties(@ModelAttribute PDFFile file)
             throws IOException {
-        // Load the document in read-only mode to prevent modifications and ensure the integrity of the original file.
+        // Load the document in read-only mode to prevent modifications and ensure the integrity of
+        // the original file.
         try (PDDocument document = pdfDocumentFactory.load(file.getFileInput(), true)) {
             PDDocumentInformation info = document.getDocumentInformation();
             Map<String, String> properties = new HashMap<>();
@@ -180,7 +181,8 @@ public class AnalysisController {
 
                 // Get permissions
                 Map<String, Boolean> permissions = new HashMap<>();
-                permissions.put("preventPrinting", !document.getCurrentAccessPermission().canPrint());
+                permissions.put(
+                        "preventPrinting", !document.getCurrentAccessPermission().canPrint());
                 permissions.put(
                         "preventModify", !document.getCurrentAccessPermission().canModify());
                 permissions.put(