fix: correct paths for python scripts and implement classpath extraction (#3984)

# Description of Changes

- **What was changed**  
- Relocated `png_to_webp.py` and `split_photos.py` from `scripts/` to
`app/core/src/main/resources/static/python/`.
- Updated `.github/labeler-config-srvaroa.yml` and
`.pre-commit-config.yaml` to include the new script directory in their
file-matching patterns.
- Added `GeneralUtils.extractScript(String scriptName)` to load Python
scripts from the classpath (`static/python/`), extract them into a
temporary directory at runtime, and return the filesystem path.

- **Why the change was made**  
- To fix the Internal Server Error caused by missing script files at
their old locations.
- Ensure the Python helper scripts are packaged inside the JAR/WAR and
reliably accessible when the application runs.
  - Only local installations were affected

---

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

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

app/common/src/main/java/stirling/software/common/configuration/InstallationPathConfig.java

@@ -14,6 +14,7 @@ public class InstallationPathConfig {
     private static final String CONFIG_PATH;
     private static final String CUSTOM_FILES_PATH;
     private static final String CLIENT_WEBUI_PATH;
+    private static final String SCRIPTS_PATH;
 
     // Config paths
     private static final String SETTINGS_PATH;
@@ -36,6 +37,7 @@ public class InstallationPathConfig {
         // Initialize config paths
         SETTINGS_PATH = CONFIG_PATH + "settings.yml";
         CUSTOM_SETTINGS_PATH = CONFIG_PATH + "custom_settings.yml";
+        SCRIPTS_PATH = CONFIG_PATH + "scripts" + File.separator;
 
         // Initialize custom file paths
         STATIC_PATH = CUSTOM_FILES_PATH + "static" + File.separator;
@@ -89,6 +91,10 @@ public class InstallationPathConfig {
         return CLIENT_WEBUI_PATH;
     }
 
+    public static String getScriptsPath() {
+        return SCRIPTS_PATH;
+    }
+
     public static String getSettingsPath() {
         return SETTINGS_PATH;
     }

app/common/src/main/java/stirling/software/common/util/GeneralUtils.java

@@ -16,6 +16,7 @@ import java.util.List;
 import java.util.Locale;
 import java.util.UUID;
 
+import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.core.io.support.ResourcePatternUtils;
@@ -33,6 +34,9 @@ import stirling.software.common.configuration.InstallationPathConfig;
 @Slf4j
 public class GeneralUtils {
 
+    private static final List<String> DEFAULT_VALID_SCRIPTS =
+            List.of("png_to_webp.py", "split_photos.py");
+
     public static File convertMultipartFileToFile(MultipartFile multipartFile) throws IOException {
         String customTempDir = System.getenv("STIRLING_TEMPFILES_DIRECTORY");
         if (customTempDir == null || customTempDir.isEmpty()) {
@@ -442,6 +446,40 @@ public class GeneralUtils {
         }
     }
 
+    /**
+     * Extracts a file from classpath:/static/python to a temporary directory and returns the path.
+     */
+    public static Path extractScript(String scriptName) throws IOException {
+        // Validate input
+        if (scriptName == null || scriptName.trim().isEmpty()) {
+            throw new IllegalArgumentException("scriptName must not be null or empty");
+        }
+        if (scriptName.contains("..") || scriptName.contains("/")) {
+            throw new IllegalArgumentException(
+                    "scriptName must not contain path traversal characters");
+        }
+
+        if (!DEFAULT_VALID_SCRIPTS.contains(scriptName)) {
+            throw new IllegalArgumentException(
+                    "scriptName must be either 'png_to_webp.py' or 'split_photos.py'");
+        }
+
+        Path scriptsDir = Paths.get(InstallationPathConfig.getScriptsPath(), "python");
+        Files.createDirectories(scriptsDir);
+
+        Path scriptFile = scriptsDir.resolve(scriptName);
+        if (!Files.exists(scriptFile)) {
+            ClassPathResource resource = new ClassPathResource("static/python/" + scriptName);
+            try (InputStream in = resource.getInputStream()) {
+                Files.copy(in, scriptFile, StandardCopyOption.REPLACE_EXISTING);
+            } catch (IOException e) {
+                log.error("Failed to extract Python script", e);
+                throw e;
+            }
+        }
+        return scriptFile;
+    }
+
     public static boolean isVersionHigher(String currentVersion, String compareVersion) {
         if (currentVersion == null || compareVersion == null) {
             return false;