feat(ui): add persistent status bar and card grid launcher

The bar is host-owned chrome: the firmware clips apps into a viewport below
it, so no app can paint over it, while /lib/statusbar.lua owns the height,
repaint interval and painting. gui.fullscreen() lets touch calibration take
the physical panel back.

Launcher and settings become grids of square cards (3 across landscape, 2
portrait) via the new gui.setTextSize, ui.label and ui.cardSide. The one
function on the `app` table moves to sys.setTickInterval, alongside the new
sys.appName the bar needs.

src/lua/bindings/input.cpp

@@ -12,7 +12,7 @@ static int l_input_getTouch(lua_State* L) {
   }
   TS_Point point = owner->touch.getPoint();
   int16_t x, y;
-  LuaApp::mapTouch(owner->tft, point, x, y);
+  owner->mapTouch(point, x, y);
   lua_pushinteger(L, x);
   lua_pushinteger(L, y);
   return 2;