chore(design): remove the walnut texture and its leftovers

Nothing paints wood any more; the texture, its credit and the legacy
--wood-* tokens go.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

public/assets/game/CREDITS.md

@@ -27,11 +27,6 @@ From **Kenney** (https://kenney.nl), all **CC0** (public domain): Casino Audio
 confirm, open, close, error), Impact Sounds (wooden pieces), Music Jingles
 (win, lose, reward, level up, match found). Trimmed and converted to mono MP3.
 
-## Table texture (`wood.webp`)
-
-"Wood Table 001" from **Poly Haven** (https://polyhaven.com), **CC0**. Resized
-and colour-graded.
-
 ## Logo (`crown.webp`, `crown-192.png`)
 
 The EL3AB crown, from the brand files in `Logo El3ab/` (owned by EL3AB / Al-Arcade).

public/css/tokens.css

@@ -65,9 +65,6 @@
   --stage-glow-2: rgba(255, 138, 52, 0.07);
   /* An eight-point star lattice, barely there: the only ornament. */
   --stage-pattern: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='56' height='56' viewBox='0 0 56 56'%3E%3Cg fill='none' stroke='%23fff' stroke-opacity='.035' stroke-width='1.2'%3E%3Cpath d='M28 12l4.7 11.3L44 28l-11.3 4.7L28 44l-4.7-11.3L12 28l11.3-4.7z'/%3E%3Cpath d='M16.7 16.7h22.6v22.6H16.7z'/%3E%3C/g%3E%3C/svg%3E");
-  /* Kept for scenes that still name them; nothing paints wood any more. */
-  --wood-img: none;
-  --wood-base: var(--stage);
   --felt-1: #22A57E;
   --felt-2: #17836A;