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/common/constants.h

@@ -0,0 +1,14 @@
+// 800x480 = 384,000 pixels
+
+#define EINK_WIDTH    800
+#define EINK_HEIGHT   480
+
+#define CORE_0 0
+#define CORE_1 1
+
+#define SYSTEM_SHUTDOWN_BIT     (1 << 0)
+#define SYSTEM_RESTART_BIT      (1 << 1)
+#define SYSTEM_START_BIT        (1 << 2)
+//
+#define DISPLAY_READY_BIT       (1 << 1)
+#define TOUCH_CALIBRATED_BIT    (1 << 2)