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-007.md

@@ -1,7 +1,7 @@
 ---
 active: true
 derived: false
-header: 'Aktor-Stromueberwachung'
+header: 'Actuator current monitoring'
 level: 1.7
 normative: true
 reviewed: null
@@ -10,6 +10,6 @@ links:
 asil: B
 ---
 
-# SYS-007: Aktor-Stromueberwachung
+# SYS-007: Actuator current monitoring
 
-Das System muss den Motorstrom jedes Aktors mit mindestens 1 kHz ueberwachen und bei Ueberschreitung von 8 A fuer mehr als 100 ms den Aktor abschalten und einen DTC setzen. Sicherheitsziel: SG-03.
+The system must monitor the motor current of each actuator at at least 1 kHz and, on exceeding 8 A for more than 100 ms, shut down the actuator and set a DTC. Safety goal: SG-003.