feat(build): enhance JaCoCo reporting with coverage summary and enforce thresholds (#5352)

# Description of Changes

### What was changed
- Refactored Gradle task configuration to use `tasks.named` and
`configureEach` for better lazy configuration and compatibility.
- Centralized JaCoCo report handling by introducing a single
`jacocoReport` task reference.
- Added a post-processing step to the JaCoCo XML report to:
  - Parse coverage metrics (LINE, INSTRUCTION, BRANCH).
  - Calculate coverage ratios.
  - Print a formatted coverage summary table directly to the build logs.
- Enabled and aligned `jacocoTestCoverageVerification` rules with
defined minimum coverage thresholds.
- Ensured the `build` task depends on the JaCoCo report to always
generate coverage output.

### Why the change was made
- To improve visibility of test coverage results directly in CI and
local builds without manually opening the HTML report.
- To enforce consistent and explicit coverage thresholds for key
metrics.
- To modernize Gradle task configuration and avoid eager task
realization.

---

> Task :proprietary:jacocoTestReport

==== JaCoCo Coverage Summary ====
Metric      | Coverage | Covered/Total | Status | Target   
------------|----------|---------------|--------|----------
LINE        | 9.01%    | 759/8426      | FAIL   | >= 16.00%
INSTRUCTION | 8.41%    | 2741/32590    | FAIL   | >= 14.00%
BRANCH      | 6.04%    | 248/4103      | FAIL   | >= 9.00% 

---

> Task :common:jacocoTestReport

==== JaCoCo Coverage Summary ====
| Metric      | Coverage | Covered/Total | Status | Target   
|------------|----------|---------------|--------|----------
LINE        | 39.47%   | 2996/7591     | PASS   | >= 16.00%
INSTRUCTION | 41.05%   | 12868/31345   | PASS   | >= 14.00%
BRANCH      | 33.43%   | 1166/3488     | PASS   | >= 9.00% 

---

> Task :stirling-pdf:jacocoTestReport

==== JaCoCo Coverage Summary ====
Metric      | Coverage | Covered/Total | Status | Target   
------------|----------|---------------|--------|----------
LINE        | 13.63%   | 2554/18741    | FAIL   | >= 16.00%
INSTRUCTION | 14.59%   | 11459/78532   | PASS   | >= 14.00%
BRANCH      | 10.68%   | 868/8124      | PASS   | >= 9.00% 

---

## 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.

.github/workflows/build.yml

@@ -97,6 +97,7 @@ jobs:
         with:
           name: test-reports-jdk-${{ matrix.jdk-version }}-spring-security-${{ matrix.spring-security }}
           path: |
+            app/**/build/reports/jacoco/test
             app/**/build/reports/tests/
             app/**/build/test-results/
             app/**/build/reports/problems/
@@ -104,6 +105,17 @@ jobs:
           retention-days: 3
           if-no-files-found: warn
 
+      - name: Add coverage to PR with spring security ${{ matrix.spring-security }} and JDK ${{ matrix.jdk-version }}
+        id: jacoco
+        uses: madrapps/jacoco-report@50d3aff4548aa991e6753342d9ba291084e63848 # v1.7.2
+        with:
+          paths: |
+            ${{ github.workspace }}/**/build/reports/jacoco/test/jacocoTestReport.xml
+          token: ${{ secrets.GITHUB_TOKEN }}
+          min-coverage-overall: 10
+          min-coverage-changed-files: 0
+          comment-type: summary
+
   check-generateOpenApiDocs:
     if: needs.files-changed.outputs.openapi == 'true'
     needs: [files-changed]