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.

tests/unit/test_apply_controller.c

@@ -1,6 +1,6 @@
 /**
  * @file test_apply_controller.c
- * @brief Unit-Tests fuer den Apply-Controller (ASIL-D Kern).
+ * @brief Unit tests for the Apply Controller (ASIL-D core).
  *
  * @reqs SWE-001 SWE-002 SWE-003 SWE-004 SWE-005
  * @arch SWA-002
@@ -56,7 +56,7 @@ static void test_null_input(void)
 
 static void test_apply_request_starts_applying(void)
 {
-    TEST_BEGIN("Apply-Request bei Stillstand -> APPLYING");
+    TEST_BEGIN("Apply request at standstill -> APPLYING");
     (void)actuator_init();
     (void)apply_ctrl_init();
     ApplyInputs in = make_idle_inputs();
@@ -68,7 +68,7 @@ static void test_apply_request_starts_applying(void)
 
 static void test_no_apply_without_standstill(void)
 {
-    TEST_BEGIN("Apply-Request ohne Stillstand wird ignoriert");
+    TEST_BEGIN("Apply request without standstill is ignored");
     (void)actuator_init();
     (void)apply_ctrl_init();
     ApplyInputs in = make_idle_inputs();
@@ -81,7 +81,7 @@ static void test_no_apply_without_standstill(void)
 
 static void test_applying_reaches_applied_on_target_force(void)
 {
-    TEST_BEGIN("APPLYING -> APPLIED wenn beide Klemmkraefte >= Target");
+    TEST_BEGIN("APPLYING -> APPLIED when both clamping forces >= target");
     (void)actuator_init();
     (void)apply_ctrl_init();
     ApplyInputs in = make_idle_inputs();
@@ -97,14 +97,14 @@ static void test_applying_reaches_applied_on_target_force(void)
 
 static void test_applying_timeout_to_error(void)
 {
-    TEST_BEGIN("APPLYING-Timeout (>30 Steps) -> ERROR");
+    TEST_BEGIN("APPLYING timeout (>30 steps) -> ERROR");
     (void)actuator_init();
     (void)apply_ctrl_init();
     ApplyInputs in = make_idle_inputs();
     in.sw_state = SWITCH_APPLY;
     apply_ctrl_step_50ms(&in);  /* -> APPLYING */
     in.sw_state = SWITCH_NEUTRAL;
-    /* Klemmkraefte bleiben bei 0 -> Timeout nach 30 Steps */
+    /* Clamping forces stay at 0 -> timeout after 30 steps */
     apply_full_cycle_until_state(&in, EPB_STATE_ERROR, 35);
     ASSERT_EQ(apply_ctrl_get_state(), EPB_STATE_ERROR);
     ASSERT_EQ(apply_ctrl_last_error(), EPB_ETIMEOUT);
@@ -113,7 +113,7 @@ static void test_applying_timeout_to_error(void)
 
 static void test_applied_holds_force(void)
 {
-    TEST_BEGIN("APPLIED haelt Klemmkraft (SWE-001)");
+    TEST_BEGIN("APPLIED maintains clamping force (SWE-001)");
     (void)actuator_init();
     (void)apply_ctrl_init();
     ApplyInputs in = make_idle_inputs();
@@ -124,18 +124,18 @@ static void test_applied_holds_force(void)
     in.right_force_n = 12000;
     apply_ctrl_step_50ms(&in);  /* -> APPLIED */
 
-    /* Klemmkraft sinkt auf 10000 (unter Toleranz-Schwelle 10800) */
+    /* Clamping force drops to 10000 (below tolerance threshold 10800) */
     in.left_force_n  = 10000;
     in.right_force_n = 10000;
     apply_ctrl_step_50ms(&in);
-    /* Apply-Controller muss nachregeln -> APPLYING */
+    /* Apply controller must re-apply -> APPLYING */
     ASSERT_EQ(apply_ctrl_get_state(), EPB_STATE_APPLYING);
     TEST_END();
 }
 
 static void test_release_requires_preconditions(void)
 {
-    TEST_BEGIN("Release ohne Engine wird abgelehnt");
+    TEST_BEGIN("Release without engine is rejected");
     (void)actuator_init();
     (void)apply_ctrl_init();
     ApplyInputs in = make_idle_inputs();
@@ -155,7 +155,7 @@ static void test_release_requires_preconditions(void)
 
 static void test_release_with_preconditions(void)
 {
-    TEST_BEGIN("Release mit allen Voraussetzungen -> RELEASING -> RELEASED");
+    TEST_BEGIN("Release with all preconditions -> RELEASING -> RELEASED");
     (void)actuator_init();
     (void)apply_ctrl_init();
     ApplyInputs in = make_idle_inputs();
@@ -180,7 +180,7 @@ static void test_release_with_preconditions(void)
 
 static void test_safety_apply_request(void)
 {
-    TEST_BEGIN("Safety-Manager Apply-Request (Hill-Hold/Auto-Apply)");
+    TEST_BEGIN("Safety Manager apply request (Hill-Hold/Auto-Apply)");
     (void)actuator_init();
     (void)apply_ctrl_init();
     ApplyInputs in = make_idle_inputs();
@@ -193,7 +193,7 @@ static void test_safety_apply_request(void)
 
 static void test_watchdog_alive_counter(void)
 {
-    TEST_BEGIN("Step-Counter steigt monoton (SWE-002 Watchdog-Alive)");
+    TEST_BEGIN("Step counter increases monotonically (SWE-002 watchdog alive)");
     (void)actuator_init();
     (void)apply_ctrl_init();
     ApplyInputs in = make_idle_inputs();
@@ -207,7 +207,7 @@ static void test_watchdog_alive_counter(void)
 
 static void test_error_state_recoverable(void)
 {
-    TEST_BEGIN("ERROR -> RELEASED bei neutralem Switch");
+    TEST_BEGIN("ERROR -> RELEASED on neutral switch");
     (void)actuator_init();
     (void)apply_ctrl_init();
     ApplyInputs in = make_idle_inputs();