TactilityKernel improvements (#464)

* **New Features**
  * Thread API with lifecycle, priority, affinity and state monitoring
  * Timer subsystem: one-shot/periodic timers, reset, pending callbacks, expiry queries
  * Expanded I²C: register-level ops, bulk writes, presence checks, ESP32 integration and new config properties
  * GPIO controller: pin level and options APIs
  * Error utilities: new error code, error-to-string, timeout helper and common macros
  * Device construction helpers (construct+start)

* **Tests**
  * New unit tests for thread and timer behavior

* **Documentation**
  * Expanded coding style guide (files/folders, C conventions)

Tactility/Source/app/i2cscanner/I2cScanner.cpp

@@ -141,11 +141,10 @@ void I2cScannerApp::onShow(AppContext& app, lv_obj_t* parent) {
     lv_obj_add_flag(scan_list, LV_OBJ_FLAG_HIDDEN);
     scanListWidget = scan_list;
 
-    auto i2c_devices = getConfiguration()->hardware->i2c;
-    if (!i2c_devices.empty()) {
-        assert(selected_bus < i2c_devices.size());
-        port = i2c_devices[selected_bus].port;
-        selectBus(selected_bus);
+    int32_t first_port;
+    if (getActivePortAtIndex(0, first_port)) {
+        lv_dropdown_set_selected(port_dropdown, 0);
+        selectBus(0);
     }
 }
 
@@ -307,12 +306,14 @@ void I2cScannerApp::onSelectBus(lv_event_t* event) {
 }
 
 void I2cScannerApp::selectBus(int32_t selected) {
-    auto i2c_devices = getConfiguration()->hardware->i2c;
-    assert(selected < i2c_devices.size());
+    int32_t found_port;
+    if (!getActivePortAtIndex(selected, found_port)) {
+        return;
+    }
 
     if (mutex.lock(100 / portTICK_PERIOD_MS)) {
         scannedAddresses.clear();
-        port = i2c_devices[selected].port;
+        port = static_cast<i2c_port_t>(found_port);
         scanState = ScanStateInitial;
         mutex.unlock();
     }