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-004.md

@@ -1,7 +1,7 @@
 ---
 active: true
 derived: false
-header: 'Klemmkraft-Erreichen bestaetigen'
+header: 'Confirm target clamping force reached'
 level: 1.4
 normative: true
 reviewed: null
@@ -10,6 +10,6 @@ links:
 asil: D
 ---
 
-# SWE-004: Klemmkraft-Erreichen bestaetigen
+# SWE-004: Confirm target clamping force reached
 
-Der Apply-Controller muss das Erreichen der Ziel-Klemmkraft via Strommessung erkennen und ein Status-Flag setzen.
+The apply controller must detect that the target clamping force has been reached via current measurement and set a status flag.