Menu screens: rock background, centred frame, logo, 3D hero

- Spielen hero panel shows the selected hero in 3D (cUI_NetGranny,
  game/ui/granny.h).
- All menu screens draw on the options' rock wall; the main menu's 1024
  frame is drawn centred over it, mouse and cursor shifted to match.
- The main menu's and options' own pictures and the main menu's 3D scene
  are left out (textures hidden by surface, scene call redirected).
- Logo top left: FX_SACREDLOGO.TGA, drawn added.
- Game textures by name (game/ui/texture.h), textured and added quads.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/mods/hud.h

@@ -26,8 +26,8 @@ int VisibleDialogTooltips(void** out, int max);
 // shifted) or event handler (mouse position shifted by the window's offset).
 int RenderCentred(void* window, int (*body)(void* context), void* context);
 int HandleCentred(void* event, int (*body)(void* context), void* context);
-// RenderCentred for full-screen windows: black beside the 1024 frame, drawn
-// with a viewport on it (as the save game and export screens).
+// RenderCentred for full-screen windows: the menu screens' background beside
+// the 1024 frame, drawn with a viewport on it (as the options in a game).
 int RenderFramed(void* window, void* device, int (*body)(void* context), void* context);
 
 // 16:9 screens (mods/screen.h): laid out on a 1365x768 canvas, centred in
@@ -40,4 +40,16 @@ int CanvasOffsetX();
 int RenderCanvas(void* window, int (*body)(void* context), void* context);
 int HandleCanvas(void* event, int (*body)(void* context), void* context);
 
+// The main menu (mods/screen.cpp): with `framed`, body(context) draws the
+// menu's 1024x768 frame centred in the render width (shifted, with a
+// viewport on it); mouse positions are then given in frame coordinates
+// (MenuFrameOffsetX, applied by the borderless mod). Without, the menu draws
+// unshifted (a 16:9 screen is shown).
+int RenderMenuFrame(void* device, bool framed, int (*body)(void* context), void* context);
+int MenuFrameOffsetX();
+
+// Quads drawn with one of these textures (Direct3D surfaces) are left out,
+// on every thread, until the list changes (at most 64).
+void SetHiddenTextures(void* const* surfaces, int count);
+
 } // namespace mods::hud