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-010.md

@@ -1,7 +1,7 @@
 ---
 active: true
 derived: false
-header: 'HMI-Statusanzeige'
+header: 'HMI status display'
 level: 1.10
 normative: true
 reviewed: null
@@ -9,6 +9,6 @@ links: []
 asil: QM
 ---
 
-# SYS-010: HMI-Statusanzeige
+# SYS-010: HMI status display
 
-Der EPB-Status muss dem Fahrer signalisiert werden: LED am Schalter (an = Apply, aus = Release, blinkend = Fehler) sowie Text im Kombi-Display via CAN-Bus (Frame-ID 0x3A0, 50 Hz).
+The EPB status must be signalled to the driver: LED on the switch (on = applied, off = released, blinking = error) and a text in the instrument cluster via CAN bus (frame ID 0x3A0, 50 Hz).