fix: never cache HTML shell (no more stale bundles); tidy trick offsets

- nginx: serve the HTML shell with Cache-Control no-store so a new deploy (new
  chunk hashes) is picked up immediately — fixes the recurring stale-bundle
  "page couldn't load" at the source. Hashed /_next/static stays immutable.
- Trick offsets set to a clean symmetric cross.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/components/GameTable.tsx

@@ -413,10 +413,10 @@ function OpponentHand({
 // Compact, centered cross — small magnitudes keep the played pile in the middle of
 // the felt (clear of the side seats/stacks). Each card still nudges toward its player.
 const TRICK_OFFSET: Record<Seat, { x: number; y: number }> = {
-  0: { x: 0, y: 52 },
-  1: { x: 50, y: 0 },
-  2: { x: 0, y: -52 },
-  3: { x: -50, y: 0 },
+  0: { x: 0, y: 50 },
+  1: { x: 48, y: 0 },
+  2: { x: 0, y: -50 },
+  3: { x: -48, y: 0 },
 };
 const TRICK_ENTER: Record<Seat, { x: number; y: number }> = {
   0: { x: 0, y: 260 },