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)

TactilityKernel/Source/drivers/i2c_controller.cpp

@@ -1,6 +1,4 @@
 // SPDX-License-Identifier: Apache-2.0
-
-#include <tactility/driver.h>
 #include <tactility/drivers/i2c_controller.h>
 #include <tactility/error.h>
 
@@ -23,6 +21,34 @@ error_t i2c_controller_write_read(Device* device, uint8_t address, const uint8_t
     return I2C_DRIVER_API(driver)->write_read(device, address, writeData, writeDataSize, readData, readDataSize, timeout);
 }
 
+error_t i2c_controller_read_register(Device* device, uint8_t address, uint8_t reg, uint8_t* data, size_t dataSize, TickType_t timeout) {
+    const auto* driver = device_get_driver(device);
+    return I2C_DRIVER_API(driver)->read_register(device, address, reg, data, dataSize, timeout);
+}
+
+error_t i2c_controller_write_register(Device* device, uint8_t address, uint8_t reg, const uint8_t* data, uint16_t dataSize, TickType_t timeout) {
+    const auto* driver = device_get_driver(device);
+    return I2C_DRIVER_API(driver)->write_register(device, address, reg, data, dataSize, timeout);
+}
+
+error_t i2c_controller_write_register_array(Device* device, uint8_t address, const uint8_t* data, uint16_t dataSize, TickType_t timeout) {
+    const auto* driver = device_get_driver(device);
+    if (dataSize % 2 != 0) {
+        return ERROR_INVALID_ARGUMENT;
+    }
+    for (int i = 0; i < dataSize; i += 2) {
+        error_t error = I2C_DRIVER_API(driver)->write_register(device, address, data[i], &data[i + 1], 1, timeout);
+        if (error != ERROR_NONE) return error;
+    }
+    return ERROR_NONE;
+}
+
+error_t i2c_controller_has_device_at_address(Device* device, uint8_t address, TickType_t timeout) {
+    const auto* driver = device_get_driver(device);
+    uint8_t message[2] = { 0, 0 };
+    return I2C_DRIVER_API(driver)->write(device, address, message, 2, timeout);
+}
+
 const struct DeviceType I2C_CONTROLLER_TYPE { 0 };
 
 }