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/M5UnitTest/main/Source/TestViewBase.h

@@ -0,0 +1,34 @@
+#pragma once
+
+#include <tt_app.h>
+#include <lvgl.h>
+
+class M5UnitTest;
+
+// Minimal interface shared by all test views.
+// To return to the list, concrete views call showList() on the owning M5UnitTest.
+// M5UnitTest calls onStop() then deletes the view after the Back button is tapped.
+class TestViewBase {
+public:
+    virtual ~TestViewBase() = default;
+    virtual void onStart(lv_obj_t* parent, AppHandle handle, M5UnitTest* app) = 0;
+    virtual void onStop() = 0;
+
+protected:
+    M5UnitTest* app_ = nullptr;
+
+    // Accent colors matching M5Stack product image palette
+    static constexpr lv_color_t COLOR_I2C  = LV_COLOR_MAKE(0x1A, 0x6E, 0xC8); // M5 blue
+    static constexpr lv_color_t COLOR_GPIO = LV_COLOR_MAKE(0xC0, 0x20, 0x20); // red
+    static constexpr lv_color_t COLOR_UART = LV_COLOR_MAKE(0x20, 0x90, 0x50); // green
+
+    // Creates a standard toolbar with a Back button that returns to the list.
+    lv_obj_t* createToolbar(lv_obj_t* parent, AppHandle handle, const char* title);
+
+    // Creates a colored identity banner strip below the toolbar.
+    // ifaceBadge: short string e.g. "I2C", "GPIO", "UART"
+    void createBanner(lv_obj_t* parent, const char* unitName,
+                      const char* ifaceBadge, lv_color_t accentColor);
+
+    static void onBackClicked(lv_event_t* e);
+};