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-006.md

@@ -1,7 +1,7 @@
 ---
 active: true
 derived: false
-header: 'Auto-Release beim Anfahren (Drive-Away-Assist)'
+header: 'Auto-release on drive-away (Drive-Away Assist)'
 level: 1.6
 normative: true
 reviewed: null
@@ -10,6 +10,6 @@ links:
 asil: B
 ---
 
-# SYS-006: Auto-Release beim Anfahren (Drive-Away-Assist)
+# SYS-006: Auto-release on drive-away (Drive-Away Assist)
 
-Wenn die Parkbremse aktiv ist und der Fahrer Anfahrabsicht zeigt (Gaspedal-Betaetigung bei eingelegtem Gang), muss das System die Parkbremse innerhalb von 500 ms loesen. Voraussetzung: alle Sicherheitskriterien (Fahrertuer geschlossen, Sicherheitsgurt) erfuellt.
+When the parking brake is engaged and the driver shows intent to drive away (throttle actuation with gear engaged), the system must release the parking brake within 500 ms. Precondition: all safety criteria (driver door closed, seatbelt fastened) are met.