feat(i18n): full English translation of demo-epb

Phase 2 of the English translation:

Word documents (filled, EPB-specific):
- 8 plans (PID, PM, QA, SWE, Test, Project Manual, CM, RM)
- 6 safety docs (HARA, Safety Case, FMEDA, MISRA Compliance,
  Verification Report, Tool Qualification Cppcheck)
- 2 manuals (User, Service)
- 3 audit artefacts (Review minutes, NC-001, MISRA-REC-001)
- All regenerated via pandoc from English markdown sources

Code, tests, headers:
- All file headers, struct comments, function docstrings in English
- All test names (TEST_BEGIN strings) translated
- Inline comments translated
- 46 tests still green after translation

CI workflows:
- All step names in English
- Step descriptions, comments, release notes template in English

README.md fully rewritten in English with proper guided tour.

Phase 3 (still pending): dev-process repo templates + toolstack/setup docs.

.gitea/workflows/validate.yml

@@ -7,7 +7,7 @@ on:
     branches: [main, develop]
 
 jobs:
-  # Build + Tests auf allen 3 OS — Linux verbindlich, Mac/Win continue-on-error
+  # Build + tests on all 3 OS — Linux required, Mac/Win continue-on-error
   build-test:
     strategy:
       fail-fast: false
@@ -33,26 +33,26 @@ jobs:
         run: |
           set +e
           echo "PATH=$PATH"
-          gcc --version 2>&1 | head -1     || echo "  (kein gcc)"
-          make --version 2>&1 | head -1    || echo "  (kein make)"
-          cppcheck --version 2>&1 | head -1 || echo "  (kein cppcheck)"
+          gcc --version 2>&1 | head -1     || echo "  (no gcc)"
+          make --version 2>&1 | head -1    || echo "  (no make)"
+          cppcheck --version 2>&1 | head -1 || echo "  (no cppcheck)"
           echo "done"
 
-      - name: Static Analysis (Cppcheck)
+      - name: Static analysis (Cppcheck)
         shell: bash
         run: make static
 
-      - name: MISRA Check
+      - name: MISRA check
         shell: bash
         run: |
-          make misra || echo "MISRA findings present (Demo non-failing)"
+          make misra || echo "MISRA findings present (demo non-failing)"
 
-      - name: Build + Unit Tests
+      - name: Build + unit tests
         shell: bash
         run: make test
 
-  # Coverage, Traceability, Diagrams, API-Doc, Test-Report — alle auf Linux,
-  # parallel zu build-test (Matrix continue-on-error wird leider nicht in needs durchgereicht)
+  # Coverage, traceability, diagrams, API doc, test report — all on Linux,
+  # parallel to build-test (matrix continue-on-error is not propagated through needs)
   reports:
     runs-on: ubuntu-latest
     steps:
@@ -67,39 +67,39 @@ jobs:
             python3 python3-pip ca-certificates \
             doxygen graphviz
 
-      - name: Build + Tests + Coverage
+      - name: Build + tests + coverage
         run: |
           make test
           make coverage
 
-      - name: Test-Summary-Report
+      - name: Test summary report
         run: make test-report
 
-      - name: Traceability Check
+      - name: Traceability check
         run: python3 tools/traceability.py check
 
-      - name: Traceability Matrix publishen
+      - name: Publish Traceability Matrix
         run: python3 tools/traceability.py publish docs/traceability
 
-      - name: PlantUML Diagramme rendern
+      - name: Render PlantUML diagrams
         run: python3 tools/render_plantuml.py
 
-      - name: Doxygen API-Dokumentation
+      - name: Doxygen API documentation
         run: make docs
 
-      - name: Cppcheck-Report (XML + HTML)
+      - name: Cppcheck Report (XML + HTML)
         run: |
           mkdir -p build
           cppcheck --enable=all --inconclusive --xml --xml-version=2 \
             -I src src 2> build/cppcheck-report.xml || true
-          # cppcheck-htmlreport ist Teil des cppcheck-Pakets
+          # cppcheck-htmlreport is part of the cppcheck package
           cppcheck-htmlreport \
             --file=build/cppcheck-report.xml \
             --report-dir=build/cppcheck-html \
             --source-dir=. \
             --title="demo-epb Cppcheck Report" || echo "htmlreport skipped"
 
-      - name: Landing-Page
+      - name: Landing page
         run: make landing-page
 
       - name: Upload Coverage HTML
@@ -109,7 +109,7 @@ jobs:
           name: coverage-html
           path: build/coverage-html/
 
-      - name: Upload Test-Report
+      - name: Upload Test Report
         uses: actions/upload-artifact@v3
         if: always()
         with:
@@ -126,40 +126,40 @@ jobs:
           name: traceability
           path: docs/traceability/
 
-      - name: Upload Architektur-Diagramme
+      - name: Upload Architecture Diagrams
         uses: actions/upload-artifact@v3
         if: always()
         with:
           name: architecture-diagrams
           path: docs/diagrams/
 
-      - name: Upload Doxygen API-Doc
+      - name: Upload Doxygen API Doc
         uses: actions/upload-artifact@v3
         if: always()
         with:
           name: api-doc
           path: build/api-doc/html/
 
-      - name: Upload Landing-Page
+      - name: Upload Landing Page
         uses: actions/upload-artifact@v3
         if: always()
         with:
           name: landing-page
           path: build/index.html
 
-      - name: Upload Cppcheck-Report
+      - name: Upload Cppcheck Report
         uses: actions/upload-artifact@v3
         if: always()
         with:
           name: cppcheck-report
           path: build/cppcheck-report.xml
 
-      - name: Deploy zu gitea.slohmaier.com/pages/demo-epb/
+      - name: Deploy to gitea.slohmaier.com/pages/demo-epb/
         if: success() && github.ref == 'refs/heads/main'
         run: |
           DEPLOY=/var/www/pages/demo-epb
           if [ ! -d "$DEPLOY" ]; then
-            echo "Mount $DEPLOY nicht da — Runner-Config pruefen. Skip."
+            echo "Mount $DEPLOY not present — check runner config. Skipping."
             exit 0
           fi
           mkdir -p "$DEPLOY"/{docs,coverage,traceability,diagrams,api-doc,reports/cppcheck,src,misra/records}