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_actuator_driver.c

@@ -1,6 +1,6 @@
 /**
  * @file test_actuator_driver.c
- * @brief Unit-Tests fuer den Actuator-Driver.
+ * @brief Unit tests for the Actuator Driver.
  *
  * @reqs SWE-006 SWE-013 SWE-014 SWE-015
  * @arch SWA-003
@@ -12,7 +12,7 @@ TestStats g_test_stats = {0, 0};
 
 static void test_init(void)
 {
-    TEST_BEGIN("init -> beide Aktoren STOP, 0 mA");
+    TEST_BEGIN("init -> both actuators STOP, 0 mA");
     ASSERT_EQ(actuator_init(), EPB_OK);
     ActuatorStatus l = actuator_get_status(ACTUATOR_LEFT);
     ActuatorStatus r = actuator_get_status(ACTUATOR_RIGHT);
@@ -61,7 +61,7 @@ static void test_release_normal(void)
 
 static void test_isr_samples_current(void)
 {
-    TEST_BEGIN("ISR-Sample setzt current_ma und peak");
+    TEST_BEGIN("ISR sample sets current_ma and peak");
     (void)actuator_init();
     (void)actuator_apply(ACTUATOR_LEFT, 80);
     actuator_isr_1khz(ACTUATOR_LEFT, 3000);
@@ -73,10 +73,10 @@ static void test_isr_samples_current(void)
 
 static void test_overcurrent_cutoff_after_100ms(void)
 {
-    TEST_BEGIN("Overcurrent > 8 A fuer 100 ms -> STOP + overcurrent flag");
+    TEST_BEGIN("Overcurrent > 8 A for 100 ms -> STOP + overcurrent flag");
     (void)actuator_init();
     (void)actuator_apply(ACTUATOR_LEFT, 80);
-    /* 100 Samples (= 100 ms bei 1 kHz) ueber 8 A */
+    /* 100 samples (= 100 ms at 1 kHz) above 8 A */
     for (int i = 0; i < 100; ++i) {
         actuator_isr_1khz(ACTUATOR_LEFT, 8500);
     }
@@ -89,7 +89,7 @@ static void test_overcurrent_cutoff_after_100ms(void)
 
 static void test_overcurrent_below_window_no_cutoff(void)
 {
-    TEST_BEGIN("Overcurrent < 100 ms loest noch nicht aus");
+    TEST_BEGIN("Overcurrent < 100 ms does not trip yet");
     (void)actuator_init();
     (void)actuator_apply(ACTUATOR_LEFT, 80);
     for (int i = 0; i < 50; ++i) {
@@ -103,7 +103,7 @@ static void test_overcurrent_below_window_no_cutoff(void)
 
 static void test_overcurrent_blocks_subsequent_apply(void)
 {
-    TEST_BEGIN("nach Overcurrent: weiterer apply -> EOVERCURRENT");
+    TEST_BEGIN("after overcurrent: subsequent apply -> EOVERCURRENT");
     (void)actuator_init();
     (void)actuator_apply(ACTUATOR_LEFT, 80);
     for (int i = 0; i < 120; ++i) {
@@ -116,11 +116,11 @@ static void test_overcurrent_blocks_subsequent_apply(void)
 
 static void test_clamping_force_estimate(void)
 {
-    TEST_BEGIN("Klemmkraft-Schaetzung aus Peak-Strom (SWE-015)");
+    TEST_BEGIN("Clamping force estimation from peak current (SWE-015)");
     (void)actuator_init();
     (void)actuator_apply(ACTUATOR_LEFT, 80);
-    actuator_isr_1khz(ACTUATOR_LEFT, 4000);  /* 4 A Peak */
-    actuator_isr_1khz(ACTUATOR_LEFT, 3500);  /* danach niedriger */
+    actuator_isr_1khz(ACTUATOR_LEFT, 4000);  /* 4 A peak */
+    actuator_isr_1khz(ACTUATOR_LEFT, 3500);  /* then lower */
     ActuatorStatus s = actuator_get_status(ACTUATOR_LEFT);
     /* F = (4000 * 2500) / 1000 = 10000 N */
     ASSERT_EQ(s.clamping_force_n, 10000);