Add full automotive RTOS project

Add kernel (Cortex-M0/M3/M4, Tricore, S32K, RISC-V ports), drivers,
middleware (CAN stack, diagnostics, safety), applications, board
support, build/test tooling, and documentation.

tests/integration/test_timing.c

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+/**
+ * @file test_timing.c
+ * @brief Integration tests for timing accuracy
+ */
+
+#include "unity.h"
+#include "kernel.h"
+#include "task.h"
+#include <string.h>
+#include <math.h>
+
+/* Timing test variables */
+static volatile uint32_t periodic_count = 0;
+static volatile uint32_t first_period_time = 0;
+static volatile uint32_t last_period_time = 0;
+static volatile uint32_t max_period_jitter = 0;
+
+/* Periodic test task */
+static void periodic_task(void* params) {
+    (void)params;
+
+    uint32_t current_time = kernel_get_tick_count();
+
+    if (periodic_count == 0) {
+        first_period_time = current_time;
+    } else {
+        uint32_t period = current_time - last_period_time;
+        if (period > max_period_jitter) {
+            max_period_jitter = period;
+        }
+    }
+
+    last_period_time = current_time;
+    periodic_count++;
+
+    while (1) {
+        kernel_delay(10);
+    }
+}
+
+/* Setup */
+void setUp(void) {
+    kernel_init();
+    periodic_count = 0;
+    max_period_jitter = 0;
+}
+
+/* Teardown */
+void tearDown(void) {
+    kernel_stop();
+}
+
+/* ============================================================================
+ * Test Cases
+ * ============================================================================ */
+
+/**
+ * @brief Test periodic task timing
+ */
+void test_periodic_timing(void) {
+    TaskConfig_t config = {
+        .name = "periodic",
+        .function = periodic_task,
+        .parameters = NULL,
+        .stack_size = 1024,
+        .priority = 1,
+        .period_ticks = 10
+    };
+
+    TaskHandle_t task = task_create(&config);
+
+    kernel_start();
+    kernel_delay(1000);  /* Run for 1 second */
+
+    /* Verify task executed */
+    TEST_ASSERT_GREATER_THAN(90, periodic_count);
+    TEST_ASSERT_LESS_THAN(110, periodic_count);
+
+    /* Verify timing accuracy */
+    TEST_ASSERT_LESS_OR_EQUAL(2, max_period_jitter);  /* Max 2ms jitter */
+}
+
+/**
+ * @brief Test delay accuracy
+ */
+void test_delay_accuracy(void) {
+    kernel_start();
+
+    uint32_t start = kernel_get_tick_count();
+    kernel_delay(100);
+    uint32_t end = kernel_get_tick_count();
+
+    uint32_t elapsed = end - start;
+
+    TEST_ASSERT_GREATER_OR_EQUAL(99, elapsed);
+    TEST_ASSERT_LESS_OR_EQUAL(102, elapsed);
+}
+
+/**
+ * @brief Test tick count
+ */
+void test_tick_count(void) {
+    kernel_start();
+
+    uint32_t start = kernel_get_tick_count();
+    kernel_delay(50);
+    uint32_t end = kernel_get_tick_count();
+
+    TEST_ASSERT_EQUAL(50, end - start);
+}
+
+/**
+ * @brief Test high-frequency task
+ */
+void test_high_frequency_task(void) {
+    TaskConfig_t config = {
+        .name = "fast_task",
+        .function = periodic_task,
+        .parameters = NULL,
+        .stack_size = 1024,
+        .priority = 0,
+        .period_ticks = 1
+    };
+
+    TaskHandle_t task = task_create(&config);
+
+    kernel_start();
+    kernel_delay(100);
+
+    /* 1ms task should execute approximately 100 times */
+    TEST_ASSERT_GREATER_THAN(90, periodic_count);
+    TEST_ASSERT_LESS_THAN(110, periodic_count);
+}
+
+/* ============================================================================
+ * Test Runner
+ * ============================================================================ */
+int main(void) {
+    UNITY_BEGIN();
+
+    RUN_TEST(test_periodic_timing);
+    RUN_TEST(test_delay_accuracy);
+    RUN_TEST(test_tick_count);
+    RUN_TEST(test_high_frequency_task);
+
+    return UNITY_END();
+}