Multi module refactor (#3640)

# Description of Changes

Migrated Stirling PDF to a multi-module structure:

* Introduced new `:stirling-pdf` module
* Moved all the core logic and features of Stirling PDF into
`:stirling-pdf`
* Updated paths of jobs and scripts

---

## 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/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)
- [ ] 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/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.

stirling-pdf/src/main/java/stirling/software/SPDF/config/WebMvcConfig.java

@@ -0,0 +1,35 @@
+package stirling.software.SPDF.config;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
+import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+import lombok.RequiredArgsConstructor;
+
+import stirling.software.common.configuration.InstallationPathConfig;
+
+@Configuration
+@RequiredArgsConstructor
+public class WebMvcConfig implements WebMvcConfigurer {
+
+    private final EndpointInterceptor endpointInterceptor;
+
+    @Override
+    public void addInterceptors(InterceptorRegistry registry) {
+        registry.addInterceptor(endpointInterceptor);
+    }
+
+    @Override
+    public void addResourceHandlers(ResourceHandlerRegistry registry) {
+        // Handler for external static resources
+        registry.addResourceHandler("/**")
+                .addResourceLocations(
+                    "file:" + InstallationPathConfig.getStaticPath(),
+                    "classpath:/static/"
+                );
+        registry.addResourceHandler("/js/**").addResourceLocations("classpath:/static/js/");
+        registry.addResourceHandler("/css/**").addResourceLocations("classpath:/static/css/");
+        // .setCachePeriod(0); // Optional: disable caching
+    }
+}