games: the uno table opens its doors

Driven in a browser for the first time, which is where three bugs were.

Every visit to /games/uno was a 500: the page was never added to the list
server.go parses into the games template set, so render() answered "unknown
page". The casino tests all call their handlers directly and never go through
render(), so nothing saw it. TestEveryCasinoPageRenders now walks the mux and
asks for every page the casino routes to.

The play script hid the first card that lit up rather than the one you clicked,
so playing any other playable card made an innocent card vanish. And on a phone
the discard sized its box but not its card, which takes its size from --uno-h,
so a full-size card hung out of a small hole and covered the colour in play.

Claude-Session: https://claude.ai/code/session_013M5nD7PgUboJXoDcYHzpuJ

internal/web/static/css/input.css

@@ -1755,7 +1755,10 @@ html[data-phase="night"] {
   @media (max-width: 639px) {
     .pete-uno-hand { --uno-h: 5.2rem; --uno-w: 3.5rem; gap: 0.3rem; }
     .pete-uno-deck { --uno-h: 5.2rem; --uno-w: 3.5rem; }
-    .pete-uno-discard { height: 5.2rem; width: 3.5rem; }
+    /* The vars, not just the box: the card in the discard is a .pete-uno-card and
+       takes its size from them, so sizing the box alone left a full-size card
+       hanging out of a small hole, on top of the colour in play. */
+    .pete-uno-discard { --uno-h: 5.2rem; --uno-w: 3.5rem; height: 5.2rem; width: 3.5rem; }
     .pete-uno-hand .pete-uno-card { padding: 0.22rem; }
     .pete-uno-oval { font-size: 1.15rem; }
     .pete-uno-seat { padding: 0.35rem 0.45rem; }