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/swe/SWE-005.md

@@ -1,7 +1,7 @@
 ---
 active: true
 derived: false
-header: 'Release-Voraussetzungen pruefen'
+header: 'Check release preconditions'
 level: 1.5
 normative: true
 reviewed: null
@@ -10,6 +10,6 @@ links:
 asil: B
 ---
 
-# SWE-005: Release-Voraussetzungen pruefen
+# SWE-005: Check release preconditions
 
-Vor jedem Release muss der Apply-Controller pruefen: Motor laeuft, Bremspedal betaetigt, Gang ist eingelegt. Andernfalls Release abweisen.
+Before any release, the apply controller must verify: engine running, brake pedal pressed, gear engaged. Otherwise reject the release.