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

arch/sys/SA-001.md

@@ -21,28 +21,28 @@ asil: D
 
 # SA-001: EPB ECU
 
-## Verantwortung
+## Responsibility
 
-Zentrales Steuergeraet der elektrischen Parkbremse. Beinhaltet alle Software-
-Komponenten und die elektronische Ansteuerung der Aktoren.
+Central control unit of the electric parking brake. Contains all
+software components and the electronic actuation of the actuators.
 
-## System-Kontext
+## System context
 
 ```plantuml
 @startuml
 node "EPB ECU" as ECU
-node "Aktor links" as AL
-node "Aktor rechts" as AR
-node "Wheel Speed Sensoren (x4)" as WS
+node "Actuator left" as AL
+node "Actuator right" as AR
+node "Wheel-speed sensors (x4)" as WS
 node "Inclinometer" as IN
-node "EPB-Schalter + LED" as SW
-node "CAN-Bus" as CAN
-node "Kombi-Display" as DI
-node "OBD-Tester" as OBD
+node "EPB switch + LED" as SW
+node "CAN bus" as CAN
+node "Instrument cluster" as DI
+node "OBD tester" as OBD
 
-ECU --> AL : PWM, I-Mess
-ECU --> AR : PWM, I-Mess
-WS --> ECU : Pulse
+ECU --> AL : PWM, I-meas
+ECU --> AR : PWM, I-meas
+WS --> ECU : pulses
 IN --> ECU : SPI
 SW --> ECU : GPIO
 ECU --> SW : LED
@@ -52,24 +52,24 @@ CAN <-> OBD
 @enduml
 ```
 
-## Schnittstellen
+## Interfaces
 
-| Schnittstelle | Typ            | Richtung |
-|---------------|----------------|----------|
-| Aktor L/R     | PWM + Shunt    | I/O      |
-| Wheel Speed   | Hall-Pulse     | In       |
-| Inclinometer  | SPI            | In       |
-| Schalter      | GPIO debounced | In       |
-| LED           | GPIO           | Out      |
-| CAN           | ISO 11898      | I/O      |
+| Interface     | Type             | Direction |
+|---------------|------------------|-----------|
+| Actuator L/R  | PWM + shunt      | I/O       |
+| Wheel speed   | Hall pulses      | in        |
+| Inclinometer  | SPI              | in        |
+| Switch        | GPIO debounced   | in        |
+| LED           | GPIO             | out       |
+| CAN           | ISO 11898        | I/O       |
 
-## Subkomponenten (Aufteilung auf SW)
+## Subcomponents (allocated to software)
 
-Realisiert in Software: alle SWA-Elemente SWA-001..SWA-010.
+Realised in software: all SWA elements SWA-001..SWA-010.
 
-## Nichtfunktionale Eigenschaften
+## Non-functional properties
 
-- Worst-Case Reaktionszeit (Schalter → Aktor-Bewegung): 250 ms
-- Flash-Bedarf: < 256 KB
-- RAM-Bedarf: < 32 KB
-- Stromaufnahme: < 200 mA (Standby) / < 30 A (Aktor-Spitze)
+- Worst-case reaction time (switch to actuator motion): 250 ms
+- Flash demand: < 256 KB
+- RAM demand: < 32 KB
+- Current: < 200 mA (standby) / < 30 A (actuator peak)