refactor: move modules under app/ directory and update file paths (#3938)

# Description of Changes

- **What was changed:**  
- Renamed top-level directories: `stirling-pdf` → `app/core`, `common` →
`app/common`, `proprietary` → `app/proprietary`.
- Updated all path references in `.gitattributes`, GitHub workflows
(`.github/workflows/*`), scripts (`.github/scripts/*`), `.gitignore`,
Dockerfiles, license files, and template settings to reflect the new
structure.
- Added a new CI job `check-generateOpenApiDocs` to generate and upload
OpenAPI documentation.
- Removed redundant `@Autowired` annotations from `TempFileShutdownHook`
and `UnlockPDFFormsController`.
- Minor formatting and comment adjustments in YAML templates and
resource files.

- **Why the change was made:**  
- To introduce a clear `app/` directory hierarchy for core, common, and
proprietary modules, improving organization and maintainability.
- To ensure continuous integration and Docker builds continue to work
seamlessly with the reorganized structure.
- To automate OpenAPI documentation generation as part of the CI
pipeline.

---

## 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.

build.gradle

@@ -66,7 +66,7 @@ allprojects {
 }
 
 tasks.register('writeVersion') {
-    def propsFile = file("$projectDir/common/src/main/resources/version.properties")
+    def propsFile = file("$projectDir/app/common/src/main/resources/version.properties")
     def propsDir = propsFile.parentFile
 
     doLast {
@@ -209,7 +209,8 @@ tasks.withType(JavaCompile).configureEach {
 licenseReport {
     projects = [project]
     renderers = [new JsonReportRenderer()]
-    allowedLicensesFile = new File("$projectDir/allowed-licenses.json")
+    allowedLicensesFile = project.layout.projectDirectory.file("app/allowed-licenses.json").asFile
+    outputDir = project.layout.buildDirectory.dir("reports/dependency-license").get().asFile.path
 }
 
 sourceSets {
@@ -260,14 +261,14 @@ static def getMacVersion(String version) {
 
 jpackage {
     dependsOn(":stirling-pdf:bootJar")
-    input = layout.projectDirectory.dir("stirling-pdf/build/libs")
+    input = layout.projectDirectory.dir("app/core/build/libs")
     destination = layout.projectDirectory.dir("build/jpackage")
     mainJar = "Stirling-PDF-${project.version}.jar"
     appName = "Stirling PDF"
     appVersion = project.version
     vendor = "Stirling PDF Inc"
     appDescription = "Stirling PDF - Your Local PDF Editor"
-    icon = layout.projectDirectory.file("stirling-pdf/src/main/resources/static/favicon.ico")
+    icon = layout.projectDirectory.file("app/core/src/main/resources/static/favicon.ico")
     verbose = true
 //    mainClass = "org.springframework.boot.loader.launch.JarLauncher"
 
@@ -309,7 +310,7 @@ jpackage {
     // MacOS-specific configuration
     mac {
         appVersion = getMacVersion(project.version.toString())
-        icon = layout.projectDirectory.file("stirling-pdf/src/main/resources/static/favicon.icns")
+        icon = layout.projectDirectory.file("app/core/src/main/resources/static/favicon.icns")
         type = ImageType.DMG
         macPackageIdentifier = "Stirling PDF"
         macPackageName = "Stirling PDF"
@@ -331,7 +332,7 @@ jpackage {
     // Linux-specific configuration
     linux {
         appVersion = project.version
-        icon = layout.projectDirectory.file("stirling-pdf/src/main/resources/static/favicon.png")
+        icon = layout.projectDirectory.file("app/core/src/main/resources/static/favicon.png")
         type = ImageType.DEB // Can also use "rpm" for Red Hat-based systems
 
         // Debian package configuration
@@ -403,12 +404,12 @@ tasks.register('jpackageMacX64') {
             commandLine 'jpackage',
                 '--type', 'dmg',
                 '--name', 'Stirling PDF (x86_64)',
-                '--input', 'stirling-pdf/build/libs',
+                '--input', 'app/core/build/libs',
                 '--main-jar', "Stirling-PDF-${project.version}.jar",
                 '--main-class', 'org.springframework.boot.loader.launch.JarLauncher',
                 '--runtime-image', file(jrePath + "/zulu-17.jre/Contents/Home"),
                 '--dest', 'build/jpackage/x86_64',
-                '--icon', 'stirling-pdf/src/main/resources/static/favicon.icns',
+                '--icon', 'app/core/src/main/resources/static/favicon.icns',
                 '--app-version', getMacVersion(project.version.toString()),
                 '--mac-package-name', 'Stirling PDF (x86_64)',
                 '--mac-package-identifier', 'Stirling PDF (x86_64)',
@@ -494,7 +495,7 @@ tasks.register('cleanTempJre') {
 }
 
 launch4j {
-    icon = "${projectDir}/stirling-pdf/src/main/resources/static/favicon.ico"
+    icon = "${projectDir}/app/core/src/main/resources/static/favicon.ico"
 
     outfile="Stirling-PDF.exe"