fix(ui): landscape board zoom/pan + rack tile rendering, shorter mobile block label

Bugs surfaced while testing in VK but present on every platform (verified across
browsers, not VK-specific):

- Rack tiles: the letter used a fixed rem size, so in landscape — where tiles shrink
  below 46px in the narrow left panel — it overflowed and dropped into the bottom-left
  corner. Size it relative to the rack (cqw, like the board's labels; the tile's own
  container-query size resolves unreliably under flex + aspect-ratio).
- Landscape board zoom positioned "in two steps": the per-frame clamp-to-max reached
  the wide axis before the tall one. Interpolate both scroll axes together by time over
  the grow/shrink transition instead (settles on zoom-out too).
- The zoomed board could not be panned with a mouse (touch scrolls the overflow:auto
  viewport natively; a mouse cannot drag-scroll a div). Add a drag-to-pan handler, active
  only while zoomed, off pending tiles, past a small movement threshold, swallowing the
  trailing click so it does not also act on a cell.
- Shorten the in-game block-confirm label ru "Блокируем?" -> "В бан?" (the long form
  overflowed the seat score chip on mobile).

ui/src/game/Rack.svelte

@@ -112,12 +112,29 @@
   /* Landscape: the rack sits in a fixed-width left panel, so the tiles share the panel width
      (capped at the portrait size) and shrink below it when the panel is narrow, instead of the
      viewport-width measure that would overflow seven tiles in a column. */
+  .rack.landscape {
+    /* Size the tile glyphs relative to the rack (the board sizes its labels the same way, on its
+       .scaler container). The tile is a flex + aspect-ratio item whose OWN container-query size
+       resolves unreliably, so the rack — which has a definite width — is the query container. A
+       fixed-rem letter overflowed the tile once it shrank below 46px in a narrow left panel and
+       dropped into the bottom-left corner. The cqw values track the rack≈7×tile relation. */
+    container-type: inline-size;
+  }
   .rack.landscape .tile {
     flex: 1 1 0;
     width: auto;
     min-width: 0;
     max-width: 46px;
   }
+  .rack.landscape .letter {
+    font-size: 6cqw;
+  }
+  .rack.landscape .val {
+    font-size: 3.1cqw;
+  }
+  .rack.landscape .star {
+    font-size: 7.6cqw;
+  }
   /* While reordering, tiles at/after the drop slot slide right to open a gap there (one
      tile width plus the rack gap), so the drop position is visible. */
   .rack.reordering .tile {