render3d: r3d_small, a renderer sized for a small UI window

Set before r3d_open: the frame's uniform ring is 2 x 4 MB (was 2 x 64), memory blocks are 8 MB with
anything over 4 MB on its own (was 64 and 16), and the descriptor pools are an eighth of a world's.
Maroon Lake's launcher window draws a picture and text and never becomes the game; its launcher home
and Settings page draw pixel-identical on it. The full-size path is unchanged (steady: STEADY OK).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/ludic.render3d/env.ludic

@@ -587,6 +587,7 @@ export state Render3dState {
   r3d_time: float = 0.0
   r3d_ready: bool = false
   r3d_plate: bool = false
+  r3d_small: bool = false        # set before r3d_open: a small UI window (a launcher) - the ring, the memory blocks and the descriptor pools sized for it
   r3d_sky_path: string = null
   r3d_debug: bool = false
   r3d_debug_shadow: bool = false