feat(i18n): remaining German comments + CI strings in English

Final residual translations found in code/comments/CI:
- .doorstop.yml: config comments, traceability mapping comments
- Doxyfile: header comment
- tools/render_plantuml.py: docstring
- tools/generate_test_report.py: docstring
- tests/unit_test_framework.h: doxygen brief + body
- tests/unit/test_safety_manager.c: section comment
- src/stubs/*.h: doxygen briefs for diag/display/inclinometer/logger/service/wheel-speed
- .gitea/workflows/release.yml: release notes 'Statische Analyse' + deploy error message

.gitea/workflows/release.yml

@@ -130,11 +130,11 @@ jobs:
 
           - All 46 unit tests green (Linux runner required)
           - Coverage measured with gcov/lcov
-          - Statische Analyse mit Cppcheck (0 Findings)
+          - Static analysis with Cppcheck (0 findings)
           - MISRA C:2012 compliance confirmed (1 Advisory deviation)
-          - Traceability verified bidirectionally (50 Items)
+          - Traceability verified bidirectionally (50 items)
 
-          ## Referenzen
+          ## References
 
           - Methodology: https://gitea.slohmaier.com/slohmaier/dev-process
           - Commit: ${{ github.sha }}
@@ -177,7 +177,7 @@ jobs:
         run: |
           DEPLOY=/var/www/pages/demo-epb
           if [ ! -d "$DEPLOY" ]; then
-            echo "Mount $DEPLOY nicht da — Runner-Config pruefen. Skip."
+            echo "Mount $DEPLOY missing - check runner config. Skip."
             exit 0
           fi
           BUNDLE="release/demo-epb-${TAG}"