feat: add Pocket Dungeon game prototype

Libraries/GameKit/Include/GameKitGrid.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <lvgl.h>
+#include <cstdint>
+
+namespace GameKit {
+
+struct GridPos {
+    int16_t x = 0;
+    int16_t y = 0;
+};
+
+inline bool operator==(GridPos a, GridPos b) { return a.x == b.x && a.y == b.y; }
+inline bool operator!=(GridPos a, GridPos b) { return !(a == b); }
+
+struct GridSpec {
+    uint8_t cols = 0;
+    uint8_t rows = 0;
+    uint16_t cellPx = 0;
+    uint16_t originX = 0;
+    uint16_t originY = 0;
+};
+
+lv_point_t gridToPx(const GridSpec& grid, GridPos pos);
+bool gridContains(const GridSpec& grid, GridPos pos);
+
+} // namespace GameKit