Kernel improvements (#485)

* **New Features**
  * Added public accessors for querying module/device start and ready state.

* **Refactor**
  * Internal state moved to opaque internal objects; module/device/driver initializers now explicitly initialize internal pointers.
  * Lifecycle handling updated to construct/destruct internal state and use accessors.

* **Tests**
  * Tests updated to use public accessors and explicit construct/destruct lifecycle calls.

* **Chores**
  * Test build/include paths and small metadata updated.

Tests/TactilityFreeRtos/Source/TimerTest.cpp

@@ -0,0 +1,44 @@
+#include "doctest.h"
+#include <Tactility/Timer.h>
+
+using namespace tt;
+
+TEST_CASE("TimerType::Periodic timers can be stopped and restarted") {
+    int counter = 0;
+    auto* timer = new Timer(Timer::Type::Periodic, 1, [&counter] { counter++; });
+    CHECK_EQ(timer->start(), true);
+    kernel::delayTicks(10);
+    CHECK_EQ(timer->stop(), true);
+    CHECK_EQ(timer->start(), true);
+    kernel::delayTicks(10);
+    CHECK_EQ(timer->stop(), true);
+    delete timer;
+
+    CHECK_GE(counter, 2);
+}
+
+TEST_CASE("TimerType::Periodic calls the callback periodically") {
+    int ticks_to_run = 10;
+    int counter = 0;
+    auto* timer = new Timer(Timer::Type::Periodic, 1, [&counter] { counter++; });
+    CHECK_EQ(timer->start(), true);
+    kernel::delayTicks(ticks_to_run);
+    CHECK_EQ(timer->stop(), true);
+    delete timer;
+
+    CHECK_EQ(counter, ticks_to_run);
+}
+
+TEST_CASE("restarting TimerType::Once timers calls the callback again") {
+    int counter = 0;
+    auto* timer = new Timer(Timer::Type::Once, 1, [&counter] { counter++; });
+    CHECK_EQ(timer->start(), true);
+    kernel::delayTicks(10);
+    CHECK_EQ(timer->stop(), true);
+    CHECK_EQ(timer->start(), true);
+    kernel::delayTicks(10);
+    CHECK_EQ(timer->stop(), true);
+    delete timer;
+
+    CHECK_EQ(counter, 2);
+}