fix(sim): real text-size scaling + correct joystick-board menu hint

Two more real-vs-sim mismatches, found after seeing the rendered UI:

1. The Clock screen's big time display (setTextSize(2)) rendered at size 1
   -- SimDisplayDriverCanvas ignored setTextSize() entirely (a leftover
   no-op from the old system-font renderer) and never overrode
   getCharWidth()/getLineHeight(), so the big-digit layout math in
   UITask.cpp's drawBig() came out wrong even once print() itself gained
   real font support. Track _text_sz, scale both metrics by it (matching
   SSD1306Display's own getCharWidth()==6*_text_sz pattern), and pass it
   through to miscFixedPrint() in target.cpp instead of a hardcoded 1.

2. The Home carousel's "<PRESS_LABEL> to open" hint said "long press to
   open" -- true only for touchscreen-only boards with no dedicated Enter
   button (PRESS_LABEL's #if UI_HAS_JOYSTICK / #else split in
   examples/companion_radio/ui-new/UITask.cpp). The sim's D-pad + OK key
   behaves like a joystick board (a SHORT Enter press opens each page;
   holding it separately reaches the real context menu via
   handleLongPress()), so showing the touchscreen wording was both
   inaccurate and different from what a real joystick board like Heltec V3
   displays. Added SIM_PLATFORM to that #if alongside UI_HAS_JOYSTICK --
   UI_HAS_JOYSTICK itself stays unset, since its other two gates
   (begin()-ing/polling real joystick MomentaryButton objects) need
   hardware the sim's target.cpp doesn't declare.

Verified in real Chromium: Clock screen shows "08:11:10" at real double
size above the normal-size date line; Home carousel now says "press Enter
to open". Full regression clean: 3 native envs, wasm companion_radio, the
2-instance+repeater mesh demo, and the long-press context-menu test.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

variants/sim/SimDisplayDriver.h

@@ -196,6 +196,7 @@ class SimDisplayDriverCanvas : public DisplayDriver {
   bool _on = false;
   int _cursor_x = 0, _cursor_y = 0;
   Color _color = LIGHT;
+  int _text_sz = 1;
 
 public:
   SimDisplayDriverCanvas() : DisplayDriver(128, 64) { }
@@ -234,10 +235,21 @@ public:
     });
   }
 
-  void setTextSize(int sz) override { /* one fixed size, like the native ASCII backend */ }
+  void setTextSize(int sz) override { _text_sz = sz; }
   void setColor(Color c) override { _color = c; }
   void setCursor(int x, int y) override { _cursor_x = x; _cursor_y = y; }
 
+  // MiscFixed's real metrics (6px advance, 9px row height -- see
+  // src/helpers/ui/MiscFixedFont.h), scaled by the current text size, same
+  // as a real board's SSD1306Display::getCharWidth()/getLineHeight() do.
+  // DisplayDriver.h's own defaults (6/8, unscaled) would make the Clock
+  // screen's setTextSize(2)/(4) big-digit layout math (drawBig()'s width
+  // centring, line spacing) come out wrong -- half-size digits crowded on
+  // top of each other -- even though print() itself renders them at the
+  // right size once _text_sz reaches it (see target.cpp).
+  int getCharWidth() const override { return 6 * _text_sz; }
+  int getLineHeight() const override { return 9 * _text_sz; }
+
   // Amber-on-black palette (a common OLED look) for LIGHT/DARK; the other
   // Color enumerators (RED/GREEN/BLUE/YELLOW/ORANGE) aren't used on the real
   // monochrome OLED boards this sim mirrors either (DisplayDriver.h's own

variants/sim/target.cpp

@@ -69,8 +69,11 @@ void SimDisplayDriverCanvas::print(const char* str) {
   gfx.setCursor(_cursor_x, _cursor_y);
   // color arg is just our own internal "lit" marker (1) -- the real on-screen
   // amber/black choice is applied once at blit time below, from _color, same
-  // as every other primitive in this class.
-  miscFixedPrint(gfx, str, 1, 1);
+  // as every other primitive in this class. sz is the real current text
+  // size (set via setTextSize(), e.g. the Clock screen's big digits) --
+  // miscFixedPrint()/miscFixedDrawGlyph() scale both the glyph pixels and
+  // the advance width by it already.
+  miscFixedPrint(gfx, str, _text_sz, 1);
 
   // startFrame() already blanks the whole canvas to black every frame, so
   // only the lit pixels need drawing here -- unlit buffer cells are already