Fixes and new apps (#30)

- M5 Unit Modules library + M5 Unit Test app
- Minor fixes for TodoList, TwoEleven, Snake, Brainfuck and Breakout
- Fixed SerialConsole to use the uart controller as it was broken in one of the many updates
- Fixed keyboard input in TwoEleven, Breakout, Magic8Ball and Snake
- Bluetooth Media Keys app, supports pressing physical keys to trigger the corresponding buttonmatrix button
- Epub Reader app

Apps/MediaKeys/main/Source/MediaKeys.h

@@ -0,0 +1,55 @@
+#pragma once
+
+#include <TactilityCpp/App.h>
+#include <lvgl.h>
+#include <tactility/drivers/bluetooth.h>
+#include <tactility/drivers/bluetooth_hid_device.h>
+#include <tt_app.h>
+#include <tt_lvgl_keyboard.h>
+#include <atomic>
+
+class MediaKeys final : public App {
+    // UI elements
+    lv_obj_t* _parent = nullptr;
+    lv_obj_t* _mainWrapper = nullptr;
+    lv_obj_t* _switchWidget = nullptr;
+    lv_obj_t* _buttonMatrix = nullptr;
+    lv_timer_t* _keyHighlightTimer = nullptr;
+    uint32_t _activeKeyBtn = LV_BTNMATRIX_BTN_NONE;
+    bool _keyboardActive = false; // true when matrix has focus group + editing mode
+
+    // HAL device handles
+    struct Device* _btDevice = nullptr;
+    struct Device* _hidDevice = nullptr;
+
+    // State - accessed from both LVGL thread and BT callback thread
+    std::atomic<bool> _isEnabled    {false};
+    std::atomic<bool> _radioEnabling{false}; // true while waiting for radio to come ON
+    std::atomic<bool> _radioWasOff  {false}; // true if MediaKeys turned the radio on (so we turn it off)
+
+    // Static event callbacks
+    static void onSwitchToggled(lv_event_t* e);
+    static void onButtonPressed(lv_event_t* e);
+    static void onKeyEvent(lv_event_t* e);
+    static void onKeyHighlightTimer(lv_timer_t* t);
+    static void btEventCallback(struct Device* device, void* context, struct BtEvent event);
+    static void sendKeyTask(void* param);
+
+    // Instance methods called by static callbacks
+    void handleSwitchToggle(bool enabled);
+    void handleButtonPress(uint32_t buttonId);
+    void startHid(); // called once radio is confirmed ON
+    void enterKeyMode();
+    void exitKeyMode();
+
+public:
+
+    MediaKeys() = default;
+    MediaKeys(const MediaKeys&) = delete;
+    MediaKeys& operator=(const MediaKeys&) = delete;
+    MediaKeys(MediaKeys&&) = delete;
+    MediaKeys& operator=(MediaKeys&&) = delete;
+
+    void onShow(AppHandle appHandle, lv_obj_t* parent) override;
+    void onHide(AppHandle appHandle) override;
+};