feat(i18n): full English translation of demo-epb

Phase 2 of the English translation:

Word documents (filled, EPB-specific):
- 8 plans (PID, PM, QA, SWE, Test, Project Manual, CM, RM)
- 6 safety docs (HARA, Safety Case, FMEDA, MISRA Compliance,
  Verification Report, Tool Qualification Cppcheck)
- 2 manuals (User, Service)
- 3 audit artefacts (Review minutes, NC-001, MISRA-REC-001)
- All regenerated via pandoc from English markdown sources

Code, tests, headers:
- All file headers, struct comments, function docstrings in English
- All test names (TEST_BEGIN strings) translated
- Inline comments translated
- 46 tests still green after translation

CI workflows:
- All step names in English
- Step descriptions, comments, release notes template in English

README.md fully rewritten in English with proper guided tour.

Phase 3 (still pending): dev-process repo templates + toolstack/setup docs.

src/apply_controller.c

@@ -5,8 +5,8 @@
  * @arch SWA-002
  * @reqs SWE-001 SWE-002 SWE-003 SWE-004
  *
- * ASIL: D. Diese Komponente ist die sicherheitskritische Kernlogik.
- * Aenderungen erfordern Technical Review mit 2 Approvals.
+ * ASIL: D. This is the safety-critical core logic.
+ * Changes require a technical review with 2 approvals.
  */
 #include <stddef.h>
 
@@ -15,9 +15,9 @@
 
 typedef struct {
     EpbState  state;
-    uint8_t   step_in_state;    /* 50ms-Ticks im aktuellen State */
+    uint8_t   step_in_state;    /* 50ms ticks in the current state */
     EpbStatus last_error;
-    uint32_t  step_count;       /* Watchdog-Alive-Counter        */
+    uint32_t  step_count;       /* Watchdog alive counter        */
 } ApplyCtx;
 
 static ApplyCtx s_ctx;
@@ -30,7 +30,7 @@ static void enter_state(EpbState new_state)
 
 static bool release_preconditions_ok(const ApplyInputs* in)
 {
-    /* @reqs SWE-005 (Release-Voraussetzungen) — hier konsumiert */
+    /* @reqs SWE-005 (Release preconditions) — consumed here */
     return in->engine_running
         && in->brake_pedal_pressed
         && in->gear_engaged;
@@ -68,7 +68,7 @@ void apply_ctrl_step_50ms(const ApplyInputs* in)
         return;
     }
 
-    /* SWE-002: Watchdog-Alive-Counter erhoehen */
+    /* SWE-002: Watchdog alive counter erhoehen */
     ++s_ctx.step_count;
 
     if (s_ctx.step_in_state < UINT8_MAX) {
@@ -85,7 +85,7 @@ void apply_ctrl_step_50ms(const ApplyInputs* in)
         break;
 
     case EPB_STATE_APPLYING:
-        /* SWE-004: Klemmkraft-Erreichen pruefen */
+        /* SWE-004: Check target clamping force reached */
         if (min_force(in) >= APPLY_TARGET_FORCE_N) {
             (void)actuator_stop(ACTUATOR_LEFT);
             (void)actuator_stop(ACTUATOR_RIGHT);
@@ -99,7 +99,7 @@ void apply_ctrl_step_50ms(const ApplyInputs* in)
         break;
 
     case EPB_STATE_APPLIED:
-        /* SWE-001: Klemmkraft halten — bei Unterschreitung nachregeln */
+        /* SWE-001: Hold clamping force — re-apply on drop */
         if (min_force(in) < (APPLY_TARGET_FORCE_N - HOLD_TOLERANCE_N)) {
             (void)actuator_apply(ACTUATOR_LEFT,  60U);
             (void)actuator_apply(ACTUATOR_RIGHT, 60U);
@@ -128,7 +128,7 @@ void apply_ctrl_step_50ms(const ApplyInputs* in)
 
     case EPB_STATE_ERROR:
     default:
-        /* Auf Reset warten; sicherer Zustand ist Apply, also kein Release */
+        /* Wait for reset; safe state is Apply, hence no release */
         if (!apply_request_present(in) && !release_request_present(in)) {
             s_ctx.last_error = EPB_OK;
             enter_state(EPB_STATE_RELEASED);