feat(i18n): tools + landing page + doorstop generator in English

Phase 1 of full English translation:
- generate_doorstop_items.py: all 55 items (SG/SYS/SWE/SA/SWA) rewritten in English
- generate_landing_page.py: full UI labels, KPI cards, section headings in English
- traceability.py: docstring, error messages, HTML headers in English
- generate_test_report.py: report content + table headers in English
- All 55 markdown items in safety/sg/, reqs/, arch/ regenerated in English

Still to come:
- demo-epb filled Word docs (PID, plans, safety, manuals, audit artefacts)
- Code comments + test names + CI workflow step names
- README + dev-process repo templates

reqs/sys/SYS-008.md

@@ -1,7 +1,7 @@
 ---
 active: true
 derived: false
-header: 'Service-Modus fuer Werkstatt'
+header: 'Service mode for the workshop'
 level: 1.8
 normative: true
 reviewed: null
@@ -9,6 +9,6 @@ links: []
 asil: QM
 ---
 
-# SYS-008: Service-Modus fuer Werkstatt
+# SYS-008: Service mode for the workshop
 
-Das System muss ueber UDS RoutineControl (Service 0x31) einen Service-Modus bereitstellen, in dem die Aktoren manuell in Wartungs-Position gefahren werden koennen (z.B. fuer Bremsbelag-Wechsel).
+The system must provide a service mode via UDS RoutineControl (service 0x31) in which the actuators can be moved manually into maintenance position (e.g. for brake pad replacement).