feat: add simcity, pacman, tetris as inline retro-game easter eggs

Generalized the doom launcher into launchGame(name) keyed by archive.org identifier; each cds into a fake .<name> folder and runs <name>.sh, same as doom.

assets/css/custom.css

@@ -276,14 +276,15 @@ body:not(.home) .menu { display: none; }
 }
 .proj-path__seg--last { font-weight: 700; }
 
-/* secret `doom` — runs inline as doom.sh inside a fake .doom folder, same
-   file-listing chrome as any other page. sized to the classic 4:3 game. */
-.doom-player {
+/* secret retro games (doom, simcity, pacman, tetris) — each runs inline as
+   <name>.sh inside a fake .<name> folder, same file-listing chrome as any
+   other page. sized to the classic 4:3 DOS/arcade aspect ratio. */
+.game-player {
   width: 100%;
   aspect-ratio: 4 / 3;
   background: #000;
 }
-.doom-player iframe {
+.game-player iframe {
   width: 100%;
   height: 100%;
   border: 0;