Add main application logic and touch handling functionality

- Implemented main application entry point in main.cpp, initializing queues and event groups.
- Created TouchHandler and EInkTouchHandler classes for handling touch events.
- Added a minimal event loop for touch processing in touch.cpp.
- Introduced unit tests for the hello world application in pytest_hello_world.py.
- Added configuration files for CI and Wokwi support.
- Created empty header files for network and UI modules.

main/touch/touch.h

@@ -0,0 +1,32 @@
+#include "info/info.h"
+
+class TouchHandler {
+public:
+  TouchHandler(QueueHandle_t touch_queue);
+  // the system_event_group is used to set touch-calibrated bit
+  virtual void init(EventGroupHandle_t system_event_group) = 0;
+  virtual void start_event_loop() = 0;
+  virtual ~TouchHandler() = 0;
+private:
+  TouchHandler(const TouchHandler&) = delete;
+  TouchHandler& operator=(const TouchHandler&) = delete;
+};
+
+class EInkTouchHandler : public TouchHandler {
+public:
+  EInkTouchHandler(QueueHandle_t touch_queue);
+  void init(EventGroupHandle_t system_event_group) override;
+  void start_event_loop() override;
+  ~EInkTouchHandler() override;
+
+private:
+  // Task adapter used for FreeRTOS task creation. Forwards to
+  // `run_event_loop()` using the `this` pointer passed as the task param.
+  static void task_adapter(void* arg);
+
+  // Instance method implementing the touch event loop.
+  void run_event_loop();
+  // prevent copying
+  EInkTouchHandler(const EInkTouchHandler&) = delete;
+  EInkTouchHandler& operator=(const EInkTouchHandler&) = delete;
+};